Category Archives: Quantum Physics
How quantum uncertainty saved the atom – Big Think
The 19th and early 20th centuries were both the best of times and the worst of times for the building block of all the matter on Earth: the atom. In 1803, John Dalton put forth what we now know as modern atomic theory: the postulate that everything is made of indivisible atoms, where every atom of the same species is identical and possesses the same properties as all other atoms of that type. When atoms are combined into chemical compounds, the possibilities become virtually endless, while different atoms themselves could be sorted into classes with similar properties based on the periodic table scheme of Dmitri Mendeleev.
But two experiments with cathode ray tubes in 1897 and with radioactive particles in 1911 demonstrated that atoms were actually composed of positively-charged, massive atomic nuclei and negatively-charged, light electrons, which instantly created a paradox. If this is what atoms were made of, then the laws of electricity and magnetism demanded that atoms would be unstable, collapsing in on themselves in only a fraction of a second. Yet atoms are observed to not only be stable, but to compose all of our tangible reality.
How, then, does physics wind up saving the atom from this catastrophic fate? The simple answer lies in the Heisenberg uncertainty principle, which not only saved the atom, but allowed us to predict their sizes. Heres the science of how.
The periodic table of the elements is sorted as it is (in row-like periods and column-like groups) because of the number of free/occupied valence electrons, which is the number one factor in determining each atoms chemical properties. Atoms can link up to form molecules in tremendous varieties, but its the electron structure of each one that primarily determines what configurations are possible, likely, and energetically favorable.
The idea of the atom goes all the way back to Ancient Greece, and the musings of an intellectual figure named Democritus of Abdera. A strong believer in a materialist viewpoint of the world that all of our experience could be explained by the physical components of reality Democritus rejected the notion of purposeful and divine influences on the world, and instead became the founder of atomism. What appeared to us as the order and regularity of the world, according to his ideas, were because there were only a finite number of building blocks that reality was assembled out of, and that these building blocks, those indivisible atoms, were the only materials needed to build up and compose all that we knew.
Experiments in the 18th century involving combustion, oxidation, and reduction led to the disproof of many alternate theories of the material Universe, while Dalton and Mendeleev described and sorted the atomic building blocks of our reality by similar physical, chemical, and bonding properties. For a time, it seemed as if we were well on our way to a complete description of reality: as being composed of atoms, which in turn built up everything else.
But it wasnt to be, as in 1897, J.J. Thomson demonstrated that atoms themselves were not indivisible, but instead had parts to them. His experiments with what were then known as cathode rays swiftly revolutionized how we thought about the nature of matter.
The traditional model of an atom, now more than 100 years old, is of a positively charged nucleus orbited by negatively charged electrons. Although the outdated Bohr model is where this picture comes from, we can arrive at a better one simply by considering quantum uncertainty.
The existence of electric charge was already known, and the relationship between charged particles and both electric and magnetic fields were uncovered previously in the 19th century: by Ampere, Faraday, and Maxwell, among others. When Thomson came along, he set out to discover the nature of cathode rays.
Matter, in other words, wasnt just made of atoms, but atoms themselves contained these negatively charged, very low-mass constituents, which are today known as electrons, inside of them.
In combination with the discovery of radioactivity where certain types of atoms were shown to spontaneously emit particles it was looking more and more like atoms themselves were actually made of smaller constituents: some type of subatomic particle must exist inside of them.
When cathode rays (blue, at left) are emitted and passed through a hole, they propagate through the remainder of the apparatus. If an electric field is applied and the apparatus has the air inside removed, the cathode particles will deflect downward, consistent with the notion that they are light, negatively charged particles: i.e., electrons.
But since atoms are electrically neutral and quite massive, rather than light like the electron, there must be some other type of particle inside an atom as well. It wasnt until 1911 that the experiments of Ernest Rutherford came to pass, which would investigate the nature of these other particles inside the atom as well.
What Rutherford did was simple and straightforward. The experiment began with a ring-shaped apparatus designed to detect particles encountering it from any direction. In the center of the ring, thinly hammered gold foil was placed of a thickness so small it couldnt be measured with early-20th century tools: likely just a few hundred or thousand atoms across.
Outside of both the ring and the foil, a radioactive source was placed, so that it would bombard the gold foil from one particular direction. The expectation was that the emitted radioactive particles would see the gold foil much the way a charging elephant would see a piece of tissue paper: theyd simply go right through as though the foil werent there at all.
Rutherfords gold foil experiment showed that the atom was mostly empty space, but that there was a concentration of mass at one point that was far greater than the mass of an alpha particle: the atomic nucleus.
But this turned out only to be true for most of the radioactive particles, not all of them. A few of themsmall in number but vitally importantbehaved as though they bounced off of something hard and immovable. Some of them scattered off to one side or the other, while others appeared to ricochet back toward their direction of origin. This early experiment provided the very first evidence that the inside of an atom wasnt a solid structure as previously envisioned, but rather consisted of an extremely dense, small core and a much more diffuse outer structure. AsRutherford himself remarked, looking back decades later,
It was quite the most incredible event that has ever happened to me in my life. It was almost as incredible as if you fired a 15-inch shell at a piece of tissue paper and it came back and hit you.
This type of experiment, where you fire a low, medium, or high-energy particle at a composite particle, is known as deep inelastic scattering, and it remains our best method for probing the internal structure of any system of particles.
If atoms had been made of continuous structures, then all the particles fired at a thin sheet of gold would be expected to pass right through it. The fact that hard recoils were seen quite frequently, even causing some particles to bounce back from their original direction, helped illustrate that there was a hard, dense nucleus inherent to each atom.
Combined with Thomsons earlier work (and notably, Rutherford was a former student of Thomsons), we now had a model for an atom that consisted of:
Rutherford, as one might be tempted to do, then went on to construct a model of the atom: a Solar System-like one, where the negatively-charged electrons orbited around the positively-charged nucleus, just like the planets of the Solar System orbited around the Sun.
But this model was fatally flawed, and even Rutherford realized it right away. Heres the problem: electrons are negatively charged, while the atomic nucleus is positively charged. When a charged particle sees another charged particle, it accelerates, owing to the electric force acting on it. But accelerating charged particles radiate electromagnetic waves i.e., light causing them to lose energy. If electrons were orbiting a nucleus, they should radiate energy away, causing their orbits to decay, which in turn should cause them to spiral into the nucleus. Simply by using the equations of classical electromagnetism, Rutherford showed that his model was unstable (on timescales of less than a second), so the stability of the atom clearly meant that something else was at play.
In the Rutherford model of the atom, electrons orbited the positively charged nucleus, but would emit electromagnetic radiation and see that orbit decay. It required the development of quantum mechanics, and the improvements of the Bohr model, to make sense of this apparent paradox.
Although, historically, it was Niels Bohr whose primitive quantum mechanical model would lead to a new theory for the atom and the idea that atoms had energy levels which were quantized, Bohrs model itself is incomplete and ad hoc in many ways. A more fundamental principle of quantum mechanics one that was not yet known to Rutherfords contemporaries in 1911 actually holds the powerful key to explaining why atoms are stable: the Heisenberg uncertainty principle.
Although it wasnt discovered until the 1920s, the Heisenberg uncertainty principle tells us that theres always an inherent uncertainty between what are known as complementary quantities in physics. The more accurately you measure/know one of these quantities, the more inherently uncertain the other one gets. Examples of these complementary quantities include:
plus many others. The most famous example, and the one that applies here, is the position-momentum uncertainty relation.
This diagram illustrates the inherent uncertainty relation between position and momentum. When one is known more accurately, the other is inherently less able to be known accurately. Other pairs of conjugate variables, including energy and time, spin in two perpendicular directions, or angular position and angular momentum, also exhibit this same uncertainty relation.
No matter how well you measure the position (x) and/or momentum (p) of each particle involved in any physical interaction, the product of their uncertainty (xp) is always greater than or equal to half of thereduced Planck constant,/2. And remarkably, just by using this uncertainty relation, along with the knowledge that atoms are made of (heavy) positively charged nuclei and (light) negatively charged electrons, you can derive not only the stability of an atom, but the physical size of an atom as well!
Travel the Universe with astrophysicist Ethan Siegel. Subscribers will get the newsletter every Saturday. All aboard!
Heres how.
The simplest law in all of electromagnetism is Coulombs law, which tells you the electric force between two charged particles. In direct analogy to Newtons law of universal gravitation, it tells you that the force between those particles is some constant, multiplied by each of the charges of the two particles involved, divided by the distance squared between them. And again, in direct analogy to Newtons gravity, you can also derive from that related quantities like:
Newtons law of universal gravitation (left) and Coulombs law for electrostatics (right) have almost identical forms, but the fundamental difference of one type vs. two types of charge open up a world of new possibilities for electromagnetism. In both instances, however, only one force-carrying particle, the graviton or the photon, respectively, is required.
Were going to figure this out for the simplest case of all atoms: the hydrogen atom, whose atomic nucleus is just a single proton. So lets take three equations for those of you hoping there would be no math, I apologize for the rest of this brief section and lets do what we can to put them together. The three equations, quite simply, are:
If we note that, approximately, electric potential energy and kinetic energy will balance out, we can set equations 2 and 3 equal to each other, and get that ke/x = p/2m. But in this case, x and p can be small, and will be dominated by quantum uncertainty. Therefore, we can approximate that x x and p p, and therefore everywhere we have a p in that equation, we can replace it with /2x. (Or, more accurately, /2x.)
So our equation then becomes ke/x /8mx, or if we solve this equation for x (multiplying both sides by x/ke), we get:
x /8mke,
which is approximately 10-11 meters, or about a tenth of an angstrom.
Although two atoms can easily have their electron wavefunctions overlap and bind together, this is only generally true of free atoms. When each atom is bound together as part of a much larger structure, the intermolecular forces can frequently keep atoms substantial distances apart, preventing strong bonds from forming except under very special circumstances. The size of an atom will never reduce to zero, but will remain finite, owing to the Heisenberg Uncertainty Principle.
The Heisenberg uncertainty principle, all on its own, is sufficient to explain why atoms dont collapse and have their electrons spiral into their nuclei. The smaller the distance between the electron and the nucleus becomes i.e., the smaller that x in the Heisenberg uncertainty equation gets the less-well-known momentum p is, and so as you squeeze the distance down to a smaller value, Heisenberg forces your momentum to rise. But higher values of momentum cause the electron to move faster, preventing it from falling in to the nucleus, after all. This is the key principle of quantum mechanics that keeps atoms stable, and that prevents the classical catastrophe of inspiral and merger from happening.
This also contains with it a profound implication: there is a lowest-energy state that a quantum mechanical system possesses, and that state is not necessarily positive, but can be positive and non-zero, as in the case of one or more electrons bound to an atomic nucleus. We call this a zero-point energy, and the fact that there is a lowest energy state has profound implications for the Universe at large. It tells us that you cant steal energy from the quantum vacuum; its already in the lowest-energy state. It tells us that there are no decays possible from the lowest-energy stable state; the lowest-energy quantum mechanical systems are stable. And it tells us that any system of quantum particles will have a lowest-energy state to it, determined by the fundamental quantum principles that govern reality. That includes the humble atom, and the Heisenberg uncertainty principle explains why, at a fundamental level, they truly are stable.
The author thanks Will Kinney, in whose excellent book An Infinity of Worlds: Cosmic Inflation and the Beginning of the Universe this explanation for the stability of the atom appears. (Now available in paperback.)
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Why this new theory on dark matter should matter to you – CSU News
Has a Charles Sturt University academic solved one of the biggest problems plaguing physicists?
This World Space Week, which runs from Wednesday 4 to Tuesday 10 October, Dr Allan Ernest, a retired Senior Lecturer with the School of Dentistry andMedical Sciences and a current Adjunct Lecturer in Wagga Wagga supervising research students is revealing his research findings on dark matter and quantum theory
He has dedicated years to his study of dark matter and understanding its origin using gravitational quantum mechanics, that is, how gravity is described according to quantum mechanics, which traditionally describes the electrical behaviour of electrons in atoms and other interactions of subatomic particles.
Dark matter is believed to comprise about 80 per cent of the universes matter but there is strong evidence to suggest that dark matter does not consist of ordinary matter like electrons, protons, and atoms.
I would guess that almost all physicists would say that the dark matter particle has to be some new particle and that it cannot be an ordinary already known particle, because of the strong observational evidence from cosmic background radiation and the origin of the light elements, Dr Ernest said.
Quantum mechanics, however, shows that a particle can be weakly interacting because of its environment, rather than its internal properties. Traditional atomic quantum theory has previously predicted the existence of these sorts of bound, dark quantum states in atoms, and this weak interaction effect with electrons in atoms is well known.
Dr Ernest said that he realised at the beginning of his research that if quantum theory was applicable to gravity, which has been shown to be true in experiments, then similar dark gravitational quantum states would also exist.
He said that, on small scales, the mathematics shows that these states would be easily destroyed and fragile, just like the atomic electron dark states in atoms.
But on galaxy scales, quantum theory predicts that the states are much more stable and could serve as the dark matter particles everyone is looking for. This means that ordinary matter particles can look like dark matter particles under the right conditions.
The mathematics is irrefutable but its potentially controversial because everyone is so convinced there must be some particle beyond the standard model, he said.
I would expect the initial reactions from most physicists to be its a ridiculous and far-fetched idea, but its easy to be trapped in a preconceived bias when youve been conditioned to think in a certain way over a long period of time, he said.
If what I am saying does explain the origin of the dark matter particle, and its hard to see how it doesnt, then billions of dollars of research money and thousands of physics careers are in jeopardy, so its understandable that as physicists we just dont want it to be true.
A galactic halo is a spherical component of galaxy which extends beyond the visible component and is comprised of the stellar halo, galactic corona and dark matter halo.
Dr Ernest can show that many dark states in the gravity well of a halo can be ordinary gas with a quantum composition that makes it look like there is only a fifth, depending on conditions.
Dr Ernest can show that according to gravitational quantum theory, gas particles in a halo can have a quantum composition that can enable the halo to consist almost entirely of ordinary gas but appear as though there is only a fraction of it present, depending on conditions.
He said the presence of these dark states means that the cross sections used to calculate how much gas is present in a halo are wrong.
Gravitational quantum mechanics shows that the cross sections for how light interacts with halo particles, used for the analysis of light element formation and cosmic background radiation variations, are wrong, and a complete reanalysis is required, he said.
Additionally, I now have some observational predictions that could be testable.
Dr Ernest said these findings have little real-world implications, but they can change our whole concept of how the universe operates, in the same way that General Relativity changed how we view space-time.
Although we have many environmental problems currently on Earth, which should be our main concern of course, it has always been the desire of humanity to understand the universe and our place in it, he said.
Solving the dark matter problem is a big step forward but knowing that quantum theory applies to gravity, and on such large scales, represents a fundamental paradigm shift in our view of the universe.
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Why this new theory on dark matter should matter to you - CSU News
A New Law of Physics Could Support the Idea We’re Living In a … – Slashdot
A physicist from the University of Portsmouth has explored whether a new law of physics could support the theory that we're living in a computer simulation. Phys.Org reports: Dr. Melvin Vopson has previously published research suggesting that information has mass and that all elementary particles -- the smallest known building blocks of the universe -- store information about themselves, similar to the way humans have DNA. In 2022, he discovered a new law of physics that could predict genetic mutations in organisms, including viruses, and help judge their potential consequences. It is based on the second law of thermodynamics, which establishes that entropy -- a measure of disorder in an isolated system -- can only increase or stay the same. Dr. Vopson had expected that the entropy in information systems would also increase over time, but on examining the evolution of these systems he realized it remains constant or decreases. That's when he established the second law of information dynamics, or infodynamics, which could significantly impact genetics research and evolution theory.
A new paper, published in AIP Advances, examines the scientific implications of the new law on a number of other physical systems and environments, including biological, atomic physics, and cosmology. Key findings include:
- Biological systems: The second law of infodynamics challenges the conventional understanding of genetic mutations, suggesting that they follow a pattern governed by information entropy. This discovery has profound implications for fields such as genetic research, evolutionary biology, genetic therapies, pharmacology, virology, and pandemic monitoring.- Atomic physics: The paper explains the behavior of electrons in multi-electron atoms, providing insights into phenomena like Hund's rule; which states that the term with maximum multiplicity lies lowest in energy. Electrons arrange themselves in a way that minimizes their information entropy, shedding light on atomic physics and stability of chemicals.- Cosmology: The second law of infodynamics is shown to be a cosmological necessity, with thermodynamic considerations applied to an adiabatically expanding universe supporting its validity. "The paper also provides an explanation for the prevalence of symmetry in the universe," added Dr. Vopson. "Symmetry principles play an important role with respect to the laws of nature, but until now there has been little explanation as to why that could be. My findings demonstrate that high symmetry corresponds to the lowest information entropy state, potentially explaining nature's inclination towards it."
"This approach, where excess information is removed, resembles the process of a computer deleting or compressing waste code to save storage space and optimize power consumption. And as a result supports the idea that we're living in a simulation."
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A New Law of Physics Could Support the Idea We're Living In a ... - Slashdot
How Daniel Roseberry became the internet’s favorite fashion designer – The Washington Post
October 10, 2023 at 9:00 a.m. EDT
American fashion designer Daniel Roseberry, the creative director of the French haute couture house Schiaparelli. (Alejandra Loaiza/for The Washington Post)
Designer Daniel Roseberry, creative director of the Parisian couture house Schiaparelli, is a simple man behind some of the strangest clothes anyone is making today.
Plain-spoken and cinema-star handsome, his fashion fantasy world is sweeping, uncomplicated and bubblegum. The clothes that come out of it are irresistible to anyone who learned about fashion not by attending fashion shows or reading magazines or wearing extraordinary garments, but by inhaling images of ridiculous and extravagant runways of the 1990s and 80s online.
His designs rise to the wildest dreams of his stans. In his Spring 2024 collection, for example, there was a black fringe top that fanned out at the neck like overly mascaraed lashes, a column skirt ruched down the center with a white life-size lobster at its crotch and Kendall Jenner in a bouffant with her hands on her hips. (The looks were so rich that the stans seem to find Jenner a letdown: its not serving, went the general consensus.)
Such outrageous clothes have made him the internets favorite fashion designer. Search his name on X, the platform formerly known as Twitter, and youll find countless posts singing his praises: daniel roseberry can do no wrong, bro daniel roseberrys MIND! he does it again!!! and, most frequently, some variation of the following: he is genius and a daddy.
Fashion fans pore over images of his new shows like the Beyhive pines for visuals and Swifties hunt for Easter eggs an affinity he embraces.
What I am trying to do is to create the fashion equivalent of pop music, Roseberry says, perched on a creamy sofa in the salon of Schiaparellis Paris couture house on the Place Vendome, the day after his ready-to-wear show last month. My mantra recently has been, What is the hook? If this look was a song, how do I get it to be as visually captivating or catchy or universally appealing as a Taylor Swift song?
He calls young fashion fans absolutely like, my number one priority. Nine times out of 10, whenever I get stopped on the street, its a student. Any theyre the ones who Im thinking about. Like, what would they love to see? Because their love of fashion is so pure.
Roseberry, 38, says he wants his fashion to be universal. What he doesnt mean is palatable but ridiculous, opulent, triumphant, fantastical. Like the hit songs he venerates, his clothes are ubiquitous despite the fact that his primary output, his handmade couture clothes, are made for just a handful of clients and even if youve never heard his name or that of the brand he designs for, youve almost certainly seen his work, and probably been perplexed, repulsed, seduced, delighted or all of the above. In an era defined by a beguiling abundance of fashion, his clothes may be the only ones that embody both the self-seriousness and hilarity of high fashion.
At President Bidens January 2021 inauguration, Lady Gaga performed in a fitted navy cashmere jacket and voluminous red skirt with a comically huge gold dove pin, a custom Schiaparelli look.
In January of this year, at the couture show in Paris, musician Doja Cat had her entire body covered in red paint and tens of thousands of crystals. The idea was, well hed run out of money. Halfway through designing the collection, whose theme was Dantes Inferno, he realized he didnt have the budget to design a devil.
Really, I started to strategically say, Okay, actually the front row is an extension of the show now. Our press budget is a different budget. He reached out to Dojas team and in an hour, he said, they were like, Done. Were doing this. Doja arrived nearly six hours before the show began to have herself covered in crystals by makeup artist Pat McGrath.
On a viewership level and an engagement level, he says, that was insane.
Most infamously, at that same show, he dressed Kylie Jenner in a fitted black gown with a life-size (and frighteningly lifelike) lions head on the bust. Naomi Campbell and Irina Shayk walked in the show in similar ensembles depicting a wolf and snow leopard, respectively.
The looks went viral, with a number of outlets questioning whether they were in poor taste. Some critics read them as goofy satires of fashions obsession with fur and other unethical materials; others denounced them as horrifying or just ugly. The hysteria continued for days, with several outlets claiming that the dresses promoted trophy hunting.
Roseberry anticipated shock and surprise, but not the vitriol: T.B.Q.H not at all, he says. Though some couture customers placed orders for the pieces, the owners of the house Italian fashion magnate Diego Della Valles Tods Group, which acquired the brand in 2007 had them placed in storage, and declined to fill the orders. They didnt want to reignite the drama, Roseberry says.
He thinks the controversy stemmed from their realism that if theyd been five percent more cartoonish or had been covered in diamonds, they would not have been a problem. It was the fact that they were so f---ing perfect.
I am so proud of them, he continues. Because in my mind, we touched on something that was truly taboo. Remember that meme that was like, a gold dress or a blue dress? It was like that. It wasnt about gender. It wasnt about race. It wasnt about class. It was literally there was nothing there. Nothing! But still, it was so appalling to certain people, and other people were so sensationalized. They loved that we caused a harmless scandal.
The dresses encapsulate Roseberrys brilliance: He has somehow combined two of the lowest common denominators in fashion memes and celebrity into a fabulous art form.
Roseberry emerged at a moment when high fashion and celebrity converged, and haute couture went pop. Designers spent much of the 1990s and 2000s politely courting actors and musicians, working with stylists to carefully reduce their runway creations to something more obvious and flattering.
But Roseberry had a prescience that couture, even if it caters to just a handful of clients, could speak to the masses, by creating viral runway spectacles and convincing celebrities to partake. These days, the ideal, especially for anyone famous under 40, is not to look sober, slim and tasteful in your Armani column gown, but to wink at and bait the online audience that is eager to mint memes from a designers output.
It was on the top of my list when I started to bring some sense of awe back to the red carpet, he says. I really wanted to install something that felt a bit reckless.
More recently, Roseberry has cultivated a ready-to-wear business that capitalizes on the mania around his couture. (His show in September, as a part of Paris Fashion Week, was ready-to-wear; couture is shown during a separate set of fashion weeks in January and July.)
Those clothes sell on Schiaparellis site and at a shop-in-shop at Bergdorfs and Neiman Marcus, the luxury stores parent department store.
Theres been an incredible, incredible response to it, says Linda Fargo, the snow-haired fashion director of Bergdorf Goodman. His bags and jewelry sell as reliably as his dresses and evening jackets.
I dont think in my career Ive seen this kind of appetite and excitement over something thats very unique. This is not wallflower clothing were talking about, Fargo says. These are statement pieces. And theyre statements that are not for everyone.
What makes Schiaparelli stand out is not merely its shock value but the exceptional quality, Fargo says. It is one of the rare lines that merges the technique and feeling of couture with ready-to-wear, she explains. Its rather scarce. You dont see these pieces everywhere.
Because his clothing is so crazy grotesque, shocking, freakish but also just plain beautiful observers have a tendency to project big ideas onto Roseberrys work where there arent any. Perhaps that is a source of its power and appeal that it stands up to any level of intellectual scrutiny you want to apply to it.
Natasha Lyonne began wearing Roseberrys clothes around the time of the release of Russian Doll, her explosive, boundary-melting artwork about a woman who dies over and over again that plunked the ambition of a Louis Buuel film into a streaming Netflix series.
Really what youre talking about is world-building, Lyonne says. How do you break space-time and how do you do it in a way that is comedic, but that sort of transcends that, so that people can meet you at whatever level youre at? There are jokes and existential inquisitions for viewers versed in quantum physics and a beautiful relationship for those who arent.
I see what Daniel does as very similar, she says. If you want a gorgeous, incredibly crafted garment that will make a womans body look incredible, then there is the perfect outfit for you. But if you want to wear that garment a level deeper and be in the mind of Andr Breton as youre walking around, then by golly, youre welcome to do that.
On the surface, at least, Roseberrys madness goes back to the houses founder, Elsa Schiaparelli. Fashion designers are often judged within their industry by the degree to which they reinterpret the codes of their founder: Does the current head of Saint Laurent capture Yves Saint Laurents androgynous cool? How does Hedi Slimane modernize the bourgeois tastefulness of Celines original designs? Yet Roseberry has a much different relationship to the woman behind the house he oversees, which she founded in 1927 and ran in the very space on the Place Vendome where Roseberry now works.
Ive never read her memoir, he says, referring to her 1954 book, Shocking Life.
I know very little about her isms. I cannot quote her except for one, which I love. She said, No one knows how to say Schiaparelli, but everyone knows what it means. That really stuck with me.
Their origin myths couldnt be more different. He grew up in an evangelical Christian family in Plano, Tex., and joined the house from Thom Browne, where he was design director.
Schiaparelli was an Italian aristocrat who palled around with Surrealists and Dadaists. Schiaparelli was considered a rival and foil to Coco Chanel; while Chanel was radically reducing womens fashion to align it with the modernist movement sweeping art and literature, she was more interested in how fashion could subvert the very conceits of tastefulness, flattery and glamour.
If Roseberrys clothes are surrealist, it is in their unexpected jumble of imagery an effect that seems more a reflection of the way images are transmitted in the 21st century than genuine avant-garde design.
Roseberry is more innocent even intent on protecting a naivet that allows him to produce his works of gleeful madness.
I dont go to fashion parties because I know that the cool crowd, they would be so disappointed if they met me. Because I am not I am, I am so not cool like that. And Elsa strikes me as a person who was like that. She was quotable. She was fabulous, he says. She was like, intimidating. And I dont really emotionally connect with people like that. I connect with the tender side.
He still seems to design from the place of a young person sitting in their room, music blasting, posters on the walls, bathed in their influences, their imagination running wild. When the output is shaped primarily not by the pursuit of originality but by enthusiasm. If he likes something he sees from another designers archive Jean Paul Gaultiers cone bras, say, or Christian Lacroixs operatic volumes hell simply use it in his own collections, like a pop star covering her idols hits. If runway gags feel cynical from other designers, Roseberrys read like mischief and play. I think it comes from a really tender place in me, and thats the hardest place to access and the hardest place to preserve.
Im always thinking what would a little kid want to reach out and touch? he continues. And that just feels so deep to me. So deep. So much deeper than the highbrow over-intellectualized fashion that other people do. Its also something that feels like a uniquely American kid culture experience. And when you recontextualize those things like Janet [Jackson], Michael [Jackson], Jurassic Park, Taylor [Swift] in the context of couture, theres a chemical reaction. And I think its very similar to Elsa being some wackadoo Italian coming in and taking a p--- all over the au courant Chanel-isms of the day.
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How Daniel Roseberry became the internet's favorite fashion designer - The Washington Post
Hubbard Excitons Caltech Physics Discovery Could Lead to … – SciTechDaily
Caltech researchers have discovered Hubbard excitons, which are excitons bound magnetically, offering new avenues for exciton-based technological applications.
In art, the negative space in a painting can be just as important as the painting itself. Something similar is true in insulating materials, where the empty spaces left behind by missing electrons play a crucial role in determining the materials properties. When a negatively charged electron is excited by light, it leaves behind a positive hole. Because the hole and the electron are oppositely charged, they are attracted to each other and form a bond. The resulting pair, which is short-lived, is known as an exciton [pronounced exit-tawn].
Excitons are integral to many technologies, such as solar panels, photodetectors, and sensors. They are also a key part of light-emitting diodes found in televisions and digital display screens. In most cases, the exciton pairs are bound by electrical, or electrostatic, forces, also known as Coulomb interactions.
Now, in a new study published in Nature Physics, Caltech researchers report detecting excitons that are not bound via Coulomb forces but rather by magnetism. This is the first experiment to detect how these so-called Hubbard excitons, named after the late physicist John Hubbard, form in real time.
In materials known as antiferromagnetic Mott insulators, electrons (orbs) are organized in a lattice structure of atoms such that their spins point up (blue) or down (pink) in an alternating pattern. This is a stable state in which the energy is minimized. When the material is hit with light, an electron will hop to a neighboring atomic site, leaving a positively charged hole where it once resided (dark orb). If the electron and hole move further apart from each other, the spin arrangement between them becomes disturbedthe spins are no longer pointing in opposite directions to their neighbors as seen in the second paneland this costs energy. To avoid this energy penalty, the electron and hole prefer to remain close to each other. This is the magnetic binding mechanism underlying the Hubbard exciton. Credit: Caltech
Using an advanced spectroscopic probe, we were able to observe in real-time the generation and decay of magnetically bound excitons, the Hubbard excitons, says study lead author Omar Mehio (PhD 23), a recent graduate student at Caltech who worked with David Hsieh, the Donald A. Glaser Professor of Physics at Caltech. Mehio is now a postdoctoral fellow at the Kavli Institute at Cornell.
In most insulators, oppositely charged electrons and holes interact with one another just as an electron and a proton bind to form a hydrogen atom, Mehio explains. However, in a special class of materials known as Mott insulators, the photo-excited electrons and holes instead bind through magnetic interactions.
Omar Mehio. Credit: Caltech
The results could have applications in the development of new exciton-related technologies, or excitonics, in which the excitons would be manipulated through their magnetic properties.
Hubbard excitons and their magnetic binding mechanism demonstrate a drastic departure from the paradigms of traditional excitonics, creating the opportunity to develop a whole ecosystem of novel technologies that are fundamentally unavailable in conventional excitonic systems, Mehio says. Having excitons and magnetism strongly intertwined in a single material could lead to new technologies that harness both properties.
To create the Hubbard excitons, the researchers applied light to a type of insulating material known as an antiferromagnetic Mott insulator. These are magnetic materials in which the electron spins are aligned in a repeating, stable pattern. The light excites the electrons, which jump to other atoms, leaving holes behind.
In these materials, when an electron or hole moves through the lattice, they leave in their wake a string of magnetic excitations, Mehio says. Imagine you tie one end of an elastic rope around your friend, and the other end around yourself. If your friend runs away from you, you will feel the rope pull you in that direction and you will begin to follow. This scenario is analogous to what happens between a photo-excited electron and the hole it leaves behind in a Mott insulator. With Hubbard excitons, the string of magnetic excitations between the pair serves the same role as the rope connecting you to your friend.
David Hsieh. Credit: Caltech
To demonstrate the existence of the Hubbard excitons, the researchers used a method called ultrafast time-domain terahertz spectroscopy, which allowed them to look for the very short-lived signatures of the excitons at very low-energy scales.
Excitons are unstable because the electrons want to go back into the holes, Hsieh explains. We have a way of probing the short time window before this recombination occurs, and that allowed us to see that a fluid of Hubbard excitons is transiently stabilized.
Reference: A Hubbard exciton fluid in a photo-doped antiferromagnetic Mott insulator by Omar Mehio, Xinwei Li, Honglie Ning, Zala Lenari, Yuchen Han, Michael Buchhold, Zach Porter, Nicholas J. Laurita, Stephen D. Wilson and David Hsieh, 14 September 2023, Nature Physics.DOI: 10.1038/s41567-023-02204-2
The study was funded by the Army Research Office, the David and Lucile Packard Foundation, the National Science Foundation, Caltechs Institute for Quantum Information and Matter (an NSF Physics Frontiers Center), Caltech, the German Research Foundation, the Gordon and Betty Moore Foundation, and the Slovenian Research Agency. Other authors include Xinwei Li, Honglie Ning (PhD 23), and Nicholas Laurita, all formerly of Caltech; Caltech graduate student Yuchen Han; Zala Lenari of the Jozef Stefan Institute in Slovenia and UC Berkeley; Michael Buchhold of the University of Cologne in Germany (and a former Caltech postdoc); and Zach Porter and Stephen Wilson of UC Santa Barbara.
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Hubbard Excitons Caltech Physics Discovery Could Lead to ... - SciTechDaily
Challenging Long-Held Assumptions: New Research Reveals How … – SciTechDaily
Researchers discovered the significant impact of nuclear spin on biological processes, specifically oxygen dynamics in chiral environments. This breakthrough could revolutionize biotechnology, quantum biology, isotope separation, and NMR technology. Credit: PNAS
A research team led by Prof. Yossi Paltiel at the Hebrew University of Jerusalem with groups from HUJI, Weizmann, and IST Austria recently conducted a study unveiling the significant influence of nuclear spin on biological activities. This discovery challenges long-held assumptions and opens up exciting possibilities for advancements in biotechnology and quantum biology.
Scientists have long believed that nuclear spin had no impact on biological processes. However, recent research has shown that certain isotopes behave differently due to their nuclear spin. The team focused on stable oxygen isotopes (16O, 17O, 18O) and found that nuclear spin significantly affects oxygen dynamics in chiral environments, particularly in its transport.
Prof. Yossi Paltiel, Hebrew University. Credit: Hebrew University of Jerusalem
The findings, published in the prestigiousProceedings of the National Academy of Sciences (PNAS), have potential implications for controlled isotope separation and could revolutionize nuclear magnetic resonance (NMR) technology.
Prof. Yossi Paltiel, the lead researcher, expressed excitement about the significance of these findings. He stated, Our research demonstrates that nuclear spin plays a crucial role in biological processes, suggesting that its manipulation could lead to groundbreaking applications in biotechnology and quantum biology. This could potentially revolutionize isotopic fractionation processes and unlock new possibilities in fields such as NMR.
Researchers have been studying the strange behavior of tiny particles in living things, funding some places where quantum effects change biological processes. For example studying bird navigation quantum effects may help some birds find their way in long journeys. In plants efficiently using sunlight for energy is affected by quantum effects.
This connection between the tiny world of particles and living beings likely goes back billions of years when life began and molecules with a special shape called chirality appeared. Chirality is important because only molecules with the right shape can do the jobs they need to in living things.
The link between chirality quantum mechanics was found in spin, which is like a tiny magnetic property. Chiral molecules can interact differently with particles based on their spin, creating something called Chiral Induced Spin Selectivity (CISS).
Scientists have found that spin affects tiny particles, like electrons, in living processes involving chiral molecules. They wanted to see if spin also affects larger particles, like ions and molecules which supply the base for biological transport. So, they did experiments with water particles that have different spins. The results showed that spin influences how water behaves in cells, entering at different speeds and reacting in a unique way when chiral molecules are involved.
This study highlights the importance of spin in the processes of life. Understanding and controlling spin could have a big impact on how living things work. It might also help improve medical imaging and create new ways to treat illnesses.
Reference: Nuclear spin effects in biological processes by Ofek Vardi, Naama Maroudas-Sklare, Yuval Kolodny, Artem Volosniev, Amijai Saragovi, Nir Galili, Stav Ferrera, Areg Ghazaryan, Nir Yuran, Hagit P. Affek, Boaz Luz, Yonaton Goldsmith, Nir Keren, Shira Yochelis, Itay Halevy, Mikhail Lemeshko and Yossi Paltiel, 31 July 2023, Proceedings of the National Academy of Sciences.DOI: 10.1073/pnas.2300828120
The research was a collaborative effort among scientists from various institutions, including the Institute of Earth Sciences and Life Sciences in Hebrew and the Weizmann Institute, with the study led by the Department of Applied Physics at Hebrew University.
Funding:NMS acknowledges the support of the Ministry of Energy, Israel, as part of the scholarship program for graduate students in the fields of energy. ML acknowledges support by the European Research Council (ERC) Starting Grant No. 801770 (ANGULON).
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Challenging Long-Held Assumptions: New Research Reveals How ... - SciTechDaily
Research shows how topology can help create magnetism at higher temperatures – Phys.org
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Researchers who have been working for years to understand electron arrangement and magnetism in certain semimetals have been frustrated by the fact that the materials only display magnetic properties if they are cooled to just a few degrees above absolute zero.
A new MIT study led by Mingda Li, associate professor of nuclear science and engineering, and co-authored by Nathan Drucker, a graduate research assistant in MIT's Quantum Measurement Group and Ph.D. student in applied physics at Harvard University, along with Thanh Nguyen and Phum Siriviboon, MIT graduate students working in the Quantum Measurement Group, is challenging that conventional wisdom.
The open-access research, published in Nature Communications, for the first time shows evidence that topology can stabilize magnetic ordering, even well above the magnetic transition temperaturethe point at which magnetism normally breaks down.
"The analogy I like to use to describe why this works is to imagine a river filled with logs, which represent the magnetic moments in the material," says Drucker, who served as the first author of the paper. "For magnetism to work, you need all those logs pointing in the same direction, or to have a certain pattern to them. But at high temperatures, the magnetic moments are all oriented in different directions, like the logs would be in a river, and magnetism breaks down.
"But what's important in this study is that it's actually the water that's changing," he continues. "What we showed is that, if you change the properties of the water itself, rather than the logs, you can change how the logs interact with each other, which results in magnetism."
In essence, Li says, the paper reveals how topological structures known as Weyl nodes found in CeAlGean exotic semi-metal composed of cerium, aluminum and germaniumcan significantly increase the working temperature for magnetic devices, opening the door to a wide range of applications.
While they are already being used to build sensors, gyroscopes, and more, topological materials have been eyed for a wide range of additional applications, from microelectronics to thermoelectric and catalytic devices. By demonstrating a method for maintaining magnetism at significantly higher temperatures, the study opens the door to even more possibilities, Nguyen says.
"There are so many opportunities people have demonstratedin this material and other topological materials," he says. "What this shows is a general way that can significantly improve the working temperature for these materials," adds Siriviboon.
That "quite surprising and counterintuitive" result will have substantial impact on future work on topological materials, adds Linda Ye, assistant professor of physics in Caltech's Division of Physics, Mathematics and Astronomy.
"The discovery by Drucker and collaborators is intriguing and important," says Ye, who was not involved in the research. "Their work suggests that electronic topological nodes not only play a role in stabilizing static magnetic orders, but more broadly they can be at play in the generation of magnetic fluctuations. A natural implication from this is that influences from topological Weyl states on materials can extend far beyond what was previously believed."
Princeton University professor of physics Andrei Bernevig agrees, called the findings "puzzling and remarkable."
"Weyls nodes are known to be topologically protected, but the influence of this protection on the thermodynamic properties of a phase is not well understood," says Andrei Bernevig, who was not involved in the work. "The paper by the MIT group shows that short-range order, above the ordering temperature, is governed by a nesting wave vector between the Weyl fermions that appear in this system possibly suggesting that the protection of the Weyl nodes somehow influences magnetic fluctuations!"
While the surprising results challenge the long-held understanding of magnetism and topology, they are the result, Li says, of careful experimentation and the team's willingness to explore areas which otherwise might go overlooked.
"The assumption had been that there was nothing new to find above the magnetic transition temperature," Li explains. "We used five different experimental approaches and were able to create this comprehensive story in a consistent way and put this puzzle together."
To demonstrate the presence of magnetism at higher temperature, the team began by combining cerium, aluminum, and germanium in a furnace to form millimeter-sized crystals of the material.
Those samples were then subjected to a battery of tests, including thermal and electrical conductivity tests, each of which revealed a clue to the material's unusual magnetic behavior.
"But we also undertook some more exotic methods to test this material," Drucker says. "We hit the material with a beam of X-rays which was calibrated to the same energy level as the cerium in the material, and then measured how that beam scattered.
"Those tests had to be done in a very large facility, in a Department of Energy national lab," he continues. "Ultimately, we had to do similar experiments at three different national labs to show that there is this hidden order there, and that's how we found the strongest evidence."
Part of the challenge, Nguyen says, is that conducting such experiments on topological materials is typically very difficult to do and usually provides only indirect evidence.
"In this case, what we did was conduct several experiments using different probes, and by putting them all together, that gives us a very comprehensive story," he says. "In this case it's five or six different clues, and a big list of instruments and measurements that played into this study."
Going forward, Li says, the team plans to explore whether the relationship between topology and magnetism can be demonstrated in other materials.
"We believe this principle is general," he says. "So we think this may be present in many other materials, which is exciting because it expands our understanding of what topology can do. We know it can play a role in increasing conductivity, and now we've shown it can play a role in magnetism as well."
Additional future work, Li says, will also address possible applications for topological materials, including their use in thermoelectric devices which convert heat into electricity. While such devices have already been used to power small devices, like watches, they are not yet efficient enough to provide power for cellphones or other, larger devices.
"We have studied many good thermoelectric materials, and they are all topological materials," Li says. "If they can show this performance with magnetism they will unlock very good thermoelectric properties. For example, this will help them to run at a higher temperature. Right now, many only run at very low temperatures to collect waste heat. A very natural consequence of this would be their ability to work at higher temperatures."
Ultimately, Drucker says, the research points to the fact that, while topological semimetals have been studied for a number of years, relatively little is understood about their properties.
"I think our work highlights the fact that, when you look over these different scales and use different experiments to study some of these materials, there are in fact some of these really important thermoelectric and electrical and magnetic properties that start to emerge," Drucker says.
"So, I think it also gives a hint not only towards how we can use these things for different applications, but also towards other fundamental studies to follow up on how we can better understand these effects of thermal fluctuations."
More information: Nathan C. Drucker et al, Topology stabilized fluctuations in a magnetic nodal semimetal, Nature Communications (2023). DOI: 10.1038/s41467-023-40765-1. http://www.nature.com/articles/s41467-023-40765-1
Journal information: Nature Communications
This story is republished courtesy of MIT News (web.mit.edu/newsoffice/), a popular site that covers news about MIT research, innovation and teaching.
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Research shows how topology can help create magnetism at higher temperatures - Phys.org
Bizarre Quantum Theory Explains Why Your Coffee Takes So Long to Drip through a Narrow Filter – Scientific American
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What happens when matter transitions from one phase to anothera solid to a liquid or a liquid to a gas? Describing these critical points precisely, in solvable mathematical terms, is no simple feat. And for theoretical physicist John Cardy, work in this area has led to insights into everything from the way fluids percolate through a network of pores to calculations of the entropy of black holes.
Cardy is one of the key developers of conformal field theory, which is a type of quantum field theory concerned with systems that look the same under translations (or movements) in any direction, rotations or scale transformations (changes in size). Imagine blowing up a photograph by a constant factor and seeing something that looks, on average, the same as the original. Going one step further, imagine blowing up that same photograph by different factors in different places. The image will be distorted, but the angles between lines will be preserved. This is called a conformal transformation. As it turns out, this kind of invariance is a key property for matter about to flip from one phase to another.
Conformal field theory acts as a bridge between different fields of physics: the underlying math is used in string theory, condensed matter physics and quantum statistical mechanics. Cardys formulas can describe the entropy of certain kinds of two-dimensional black holes that are used as models of the real thing. They can describe how fluids move through networks of pores when new nodes are added. This explains quantitatively why your morning coffee takes longer to percolate through a tall, narrow filter than a short, wide one, but it also has a lot of implications for fundamental physics. (More on this below.)
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Cardy, age 76, is being honored for this lifetime of contributions with a Breakthrough Prize, a prestigious award founded in 2012 by Silicon Valley innovators. Cardy is splitting the 2024 Breakthrough Prize in Fundamental Physics with Alexander Zamolodchikov, another giant of quantum field theory now at Stony Brook University.
Scientific American caught up with Cardy, an emeritus fellow at All Souls College of the University of Oxford, to talk about the work that earned the 2024 prize.
[An edited transcript of the interview follows.]
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How does it feel to have won this prize?
Im very, very pleased that the Breakthrough committee has chosen to recognize my work in this particular way. I dont work in particle physics or cosmology; I work in condensed matter physics. But my work is as fundamental as any work in those areas because the mathematics we use to describe it is very similar to work in string theory and that kind of thing. Im happy.
How do you explain to people outside of physics what your research is about?
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I work in statistical physics, which deals with any situation where you have a large number of things. That could be molecules, or atoms, or stars in the galaxy or people in a large crowd, even. This subject was, in fact, invented in the 19th century, but the thing that became of interest toward the end of the 20th century was using statistical physics to describe different states of matter and, in particular, to try to explain the phase transitions that happen when you go from one state of matter to another, such as from a solid to a liquid, for example.
In the late 1960s and early 1970s it was realized that these phase transitions can be described by the same kind of quantum field theory that had already been developed to understand elementary particle physics. It was the same mathematical structure.
But the kind of quantum field theories that we were dealing with arent the weakly interacting kinds that people had looked at in previous contexts. [Weak and strong interactions are two fundamental forces in physics. Strong attractions hold together subatomic particles such as protons and neutrons, and weak interactions govern radioactive decay.] One had to somehow develop the kinds of mathematics that could treat the system as a whole as strongly interacting. That came along in the 1980s when there were a series of papers by some Russian physicists, including Zamolodchikov, who Im sharing the award with.
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Its a subject called conformal field theory. It turns out that these [conformal] systems, when theyre at phase transitions, have very special geometric properties that allow for some strong constraints that let you solve them exactlynot in some approximation.
We don't really think about something such as phase transitions in fluids flowing through a network of pores such as a coffee filter. What is the phase transition that occurs in this situation?
Instead of temperature, the control parameter is the proportion of pores that are open. We imagine that each pore is open with probability p and closed with probability 1 p independently. If p is small, the fluid doesn't flow through the network; if p is close to 1, it does. Somewhere in between is a critical value, called the percolation threshold, at which the fluid begins to flow all the way across the network. It turns out that the percolation threshold is analogous to the critical temperature. We get universal power laws, and the system is scale invariant: if you take a photograph of the fluid flowing through the pores and blow it up, it looks like the original. It is also conformally invariant: if you blow up the photograph by different factors in different places, it also looks the sameat least on large enough scales.
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In two dimensions, conformal invariance using conformal field theory was powerful enough to predict the exact values of the critical exponents (the indices of the power laws), as well as the shape dependence. For example, how does the probability that the fluid can flow from top to bottom across a rectangle depend on the ratio of its height to its width? This is the Cardy formula.
To get ridiculously concrete with it, why does thisas you saidexplain why your morning coffee is slower to percolate through a tall, narrow filter? What's the physical process that this math is describing?
In a wider filter, there are more potential paths for the fluid to take. If it is taller, however, each path has to go farther.
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How did your work open these new doors for mathematicians to solve problems related to percolation theory?
This result puzzled mathematicians who had been working on these kinds of problems. In fact, the story is as follows: I got a message from a mathematician at Princeton University saying that they had numerical evidence that this quantity might be universal (that is, independent of microscopic details), and did I know the precise formula? I thought about it for a week or so and came up with the formula. But to be sure, I asked them to send me their data before I sent them the formula. When I overlaid the graph of their data on my predicted curve, it fit perfectly! It was one of those aha! moments one sometimes, but rarely, gets in science.
The mathematicians were not happy about my nonrigorous arguments, however. A different group developed a different approach called SchrammLoewner evolution (SLE), which describes the actual path that the fluid takes as it percolates through the network. After a lot of mathematics, this reproduces my formula and gives many other results.
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Why is this kind of work so important?
A lot of the public has the idea that in order to be fundamental, physics has to be either very smallparticle physics or string theoryor it has to be cosmology. But there is this modern idea of emergence that on different scales of energy and distance, new phenomena arise. A good example is superconductivity in a metal, which is described by quantum field theory.
You can develop the theory of a superconductor without knowing anything about particle physics. The actual description is in terms of quantum fields. Its just as interesting and just as fundamental, in a way. We can think about waves on the ocean. Theyre described by equations which are sufficient enough to explain everything we know about waves, but we dont need to know theyre made out of water molecules. This idea of emergence has developed rather gradually. Its a different way of understanding how the different sciences relate to one another.
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What is the quantum quench?
Im quite proud of having coined that term! Its an obvious term because it rolls off the tongue. A quench means when you change the external parameters of an experiment almost instantaneously. The name comes from subjects such as metallurgy. When you quench an alloy, you heat it up, and then you plunge it into cold water and alter the temperature almost instantaneously. That freezes the impurities in the alloy in place. Thats what we call a thermal quench.
So a quantum quench is when you have a quantum system that you prepare in a certain state, and then you change a magnetic field or something and watch what happens. All sorts of many-body quantum effects occur. The interesting thing is the way the quantum entanglement of the system grows as a function of time. [Entanglement refers to particles that are linked to one another despite being physically far apart; in a system of growing quantum entanglement, more particles will become linked over time.] I realized that conformational field theory was a good model for this kind of process. You cant really simulate this on a digital computer because its too complicated. It will take longer than the age of the universe to simulate this kind of problem. You can do it on a quantum computerIm not an expert on quantum computing, but Ive done this, which has informed some of that work.
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Are there any other aspects of your work that were particularly rewarding?
Its all rewarding. Ever since I was quite young, I thought I was going to be a scientist, though obviously at that age I didnt realize exactly what it entailed. I am very pleased I was able to make a success of it because there were certainly times when I was younger, as a graduate student and a postdoc, when it seemed really, really hard.
I understand you have spent a lot of time climbing. Does that hobby scratch a similar itch to physics, or is it a total escape?
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I started climbing as a teenager, and I have always tried to fold that in with my work and my travel. There are a lot of physicists and mathematicians who are interested in climbing. Its something to do with problem-solving, but the thing about climbing is that you have to solve the immediate problem in front of you in a cool way so you dont panic or fall off. The other aspect is just being out in nature and the beauty of the mountains.
Now I paint. I love to get out into the mountains, so even though Im not as energetic and cant climb them these days, I enjoy just painting them.
I was diagnosed with Parkinsons about five or six years ago, and Im really pleased to see that there is also going to be a Breakthrough Prize in Life Sciences for the study of Parkinsons. [Researchers Thomas Gasser, Ellen Sidransky and Andrew Singleton are sharing that prize for their discovery of risk genes for the neurological disease.] Its something that affects more than one million Americans and more worldwide, and its actually increasing. People should understand that (a) a lot of people have it, and (b) it doesnt stop them living and pursuing a meaningful life.
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Stanislav Kondrashov Unveils the Unfathomable in the Enigmatic … – Shoreline Beacon
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Stanislav Kondrashov's piece on Quantum Physics Provides an Overview of the Concept. The article aims to widen understanding, covering topics from quantum entanglement to the Uncertainty Principle.
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Published Sep 26, 2023 3 minute read
Lugano, Switzerland(Newsfile Corp. September 26, 2023) The article The Mysteries of Quantum Physics by Stanislav Kondrashov, which is anticipated to contribute to important discussions in the scientific community and beyond, offers a deep dive into the realm of quantum physics, elucidating its core principles and examining its implications for the future of science and technology.
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The publication introduces readers to the enigmatic world of quantum physics. It begins by discussing the dual nature of particles, which behave as particles and waves depending on the observers perspective. The piece then moves on to explore the phenomenon of quantum entanglement, wherein two particles become so closely linked that the state of one immediately affects the other, regardless of distance.
Stanislav also explores Werner Heisenbergs Uncertainty Principle, explaining that its impossible to precisely measure a particles position and momentum simultaneously. This is followed by an examination of the concept of quantum superposition, most famously illustrated by Schrodingers cat thought experiment, which suggests a particle exists in multiple states until observed.
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The article further describes the peculiar ability of particles to tunnel through barriers as if by magic, a phenomenon known as quantum tunneling. It then moves on to outline the nature of particles as vibrations on quantum fields, likened to waves in an ocean.
Kondrashov concludes by touching on the potential of quantum computing to solve, heretofore impossible problems and discussing the ongoing search for a unified theory that reconciles quantum mechanics with general relativity. The article also takes a moment to reflect on the inherent beauty and complexity of the quantum world, inviting readers to ponder the unimaginable possibilities it holds for our understanding of existence.
The piece serves as an insightful resource for a diverse audience, ranging from students and educators to professionals in scientific research and technology. It is now available for reading and sharing across various academic journals and online platforms.
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Interested readers are invited to read the full article and watch the accompanying video. All are invited to take a look at Stanislavs social media channels and other blogs for more thought-provoking pieces. Links to Kondrashovs Social Media channels are readily available for further engagements and insights below.
For more insights and content from Stanislav Kondrashov, visit http://www.stanislavkondrashov.com.
About Stanislav Kondrashov:
Stanislav is a dedicated writer, consistently exploring subjects with depth and nuance. Stanislavs approach to sharing his experiences is a testament to his commitment to unveiling the stories and philosophies shaping our world. Furthermore, Kondrashov is a world traveler who appreciates every locations natural wonders. In his travels, Stanislav refined his interests and learned about his passions: architecture, art, history, and local cuisines. Stanislav values connection- both familial and civic.
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Stanislav Kondrashov Unveils the Unfathomable in the Enigmatic ... - Shoreline Beacon
Canceling Noise: MIT’s Innovative Way To Boost Quantum Devices – SciTechDaily
By Peter Reuell, MIT Department of Nuclear Science and EngineeringSeptember 24, 2023
MIT physicists, inspired by noise-canceling headphones, have advanced the coherence time of quantum bits by 20-fold, marking significant progress for quantum computing. The team used an unbalanced echo technique to counteract system noise, and they believe further improvements are possible. This breakthrough has vast potential, from quantum sensors in biology to advancements in quantum memory.
For years, researchers have tried various ways to coax quantum bits or qubits, the basic building blocks of quantum computers to remain in their quantum state for ever-longer times, a key step in creating devices like quantum sensors, gyroscopes, and memories.
A team of physicists from MIT have taken an important step forward in that quest, and to do it, they borrowed a concept from an unlikely source noise-canceling headphones.
Led byJu Li, the Battelle Energy Alliance Professor in Nuclear Engineering and professor of materials science and engineering, andPaola Cappellaro, the Ford Professor of Engineering in the Department of Nuclear Science and Engineering and Research Laboratory of Electronics, and a professor of physics, the team described a method to achieve a 20-fold increase in the coherence times for nuclear-spin qubits. The work is described in a paper published inPhysical Review Letters. The first author of the study isGuoqing Wang PhD 23, a recent doctoral student in Cappellaros lab who is now a postdoc at MIT.
This quantum sensor in the MIT Quantum Engineering Group is based on NV centers in diamond. It was designed and built by the research team. Credit: Photo courtesy of the researchers
This is one of the main problems in quantum information, Li says. Nuclear spin (ensembles) are very attractive platforms for quantum sensors, gyroscopes, and quantum memory, (but) they have coherence times on the order of 150 microseconds in the presence of electronic spins and then the information just disappears. What we have shown is that, if we can understand the interactions, or the noise, in these systems, we can actually do much better.
In much the same way noise-canceling headphones use specific sound frequencies to filter out surrounding noise, the team developed an approach they dubbed an unbalanced echo to extend the systems coherence time.
By characterizing how a particular source of noise in this case, heat affected nuclear quadrupole interactions in the system, the team was able to use that same source of noise to offset the nuclear-electron interactions, extending coherence times from 150 microseconds to as long as 3 milliseconds.
Those improvements, however, may only be the beginning. More advances may be possible, says Wang, first author of the study who came up with the protection protocol, as they explore other possible sources of noise.
In theory, we could even improve it to hundreds or even thousands of times longer. But in practice, there may be other sources of noise in the system, and what weve shown is that if we can describe them, we can cancel them.
The paper will have significant impact on future work on quantum devices, says Dmitry Budker, leader of the Matter-Antimatter Section of the Helmholtz Institute Mainz, professor at the Johannes Gutenberg University and at the University of California at Berkeley, who was not involved in the research.
(This group is) the world leaders in the field of quantum sensing, he says. They constantly invent new approaches to stimulate developments in this booming field. In this work, they demonstrate a practical way to stretch nuclear coherence time by an order of magnitude with an ingenious spin-echo technique that should be relatively straightforward to implement in applications.
Cornell University professor of applied and engineering physics Gregory Fuchs calls the work innovative and impactful.
This (work) is important because although nuclear spin can in principle have much longer coherence lifetimes than the electron spins native to the NV centers, it has been challenging for anyone to observe long-lived nuclear spin ensembles in diamond NV center experiments, he says. What Professor Cappellaro and her students have shown is a rather unexpected strategy for doing that. This approach can be highly impactful for applications of nuclear spin ensembles, such as for rotation sensing (a gyroscope).
The experiments and calculations described in the paper deal with a large ensemble approximately 10 billion of atomic-scale impurities in diamond known as nitrogen vacancy centers, or NV centers, each of which exists in a specific quantum spin state for the nitrogen-14 nucleus, as well as a localized electron nearby.
While they have long been identified as an ideal candidate for quantum sensors, gyroscopes, memories, and more, the challenge, Wang explains, lay in working out a way to get large ensembles of NV centers to work together.
If you think of each spin as being like a clock, these 10 billion clocks are all slightly different and you cannot measure them all individually, Wang says. What we see is when you prepare all these clocks, they are initially in sync with each other at the beginning, but after some time, they completely lose their phase. We call this their de-phasing time.
The goal is to use a billion clocks but achieve the same de-phasing time as a single clock, he continues. That allows you to get enhancements from measuring multiple clocks, but at the same time you preserve the phase coherence, so you dont lose your quantum information as fast.
The underlying theory of temperature heterogeneity induced de-phasing, which relates to the materials properties, was first outlined in March by a team of researchers that included Li, Cappellaro, Wang, and other MIT graduate students. That paper, published in the Journal of Physical Chemistry Letters, described a theoretical approach for calculating how temperature and strain affect different types of interactions which can lead to decoherence.
The first, known as nuclear quadrupole interaction, occurs because the nitrogen nucleus acts as an imperfect nuclear dipole essentially a subatomic magnet. Because the nucleus is not perfectly spherical, Wang explains, it deforms, disrupting the dipole, which effectively interacts with itself. Similarly, hyperfine interaction is the result of the nucleus magnetic dipole interacting with the nearby electron magnetic dipole. Both of these two types of interactions can vary spatiotemporally, and when considering an ensemble of nuclear spin qubits, de-phasing can happen since clocks at different locations can get different phases.
Based on their earlier paper, the team theorized that, if they could characterize how those interactions were affected by heat, they would be able to offset the effect and extend coherence times for the system.
Temperature or strain affects both of those interactions, Wang says. The theory we described predicted how temperature or strain would affect the quadrupole and hyperfine, and then the unbalanced echo we developed in this work is essentially canceling out the spectral drift due to one physical interaction using another different physical interaction, utilizing their correlation induced by the same noise.
The key novelty of this work, compared to existing spin echo techniques commonly used in the quantum community, is to use different interaction noises to cancel each other such that the noises to be canceled can be highly selective. Whats exciting, though, is that we can use this system in other ways, he continues. So, we could use this to sense temperature or strain field spatiotemporal heterogeneity. This could be quite good for something like biological systems, where even a very minute temperature shift could have significant effects.
Those applications, Wang says, barely scratch the surface of the systems potential applications.
This system could also be used to examine electrical currents in electric vehicles, and because it can measure strain fields, it could be used for non-destructive structural health evaluation, Li says. You could imagine a bridge, if it had these sensors on it, we could understand what type of strain its experiencing. In fact, diamond sensors are already used to measure temperature distribution on the surface of materials, because it can be a very sensitive, high spatial resolution sensor.
Another application, Li says, may be in biology. Researchers have previously demonstrated that the use of quantum sensors to map neuronal activity from electromagnetic fields could offer potential improvements, enabling a better understanding of some biological processes.
The system described in the paper could also represent a significant leap forward for quantum memory.
While there are some existing approaches to extending the coherence time of qubits for use in quantum memory, those processes are complex, and typically involve flipping or reversing the spin of the NV centers. While that process works to reverse the spectral drift that causes decoherence, it also leads to the loss of whatever information was encoded in the system.
By eliminating the need to reverse the spin, the new system not only extends the coherence time of the qubits, but prevents the loss of data, a key step forward for quantum computing.
Going forward, the team plans to investigate additional sources of noise like fluctuating electrical field interference in the system with the goal of counteracting them to further increase coherence time.
Now that weve achieved a 20-fold improvement, were looking at how we can improve it even more, because intrinsically, this unbalanced echo can achieve an almost infinite improvement, Li says. We are also looking at how we can apply this system to the creation of a quantum gyroscope, because coherence time is just one key parameter to building a gyroscope, and there are other parameters were trying to optimize to (understand) the sensitivity we can achieve compared to previous techniques.
Reference: Characterizing Temperature and Strain Variations with Qubit Ensembles for Their Robust Coherence Protection by Guoqing Wang, Ariel Rebekah Barr, Hao Tang, Mo Chen, Changhao Li, Haowei Xu, Andrew Stasiuk, Ju Li and Paola Cappellaro, 25 July 2023, Physical Review Letters.DOI: 10.1103/PhysRevLett.131.043602
This work was supported in part by the Defense Advanced Research Projects Agency DRINQS program, the National Science Foundation, and the Defense Threat Reduction Agency Interaction of Ionizing Radiation with Matter University Research Alliance. The calculations in this work were performed in part on the Texas Advanced Computing Center and the MIT engaging cluster.
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Canceling Noise: MIT's Innovative Way To Boost Quantum Devices - SciTechDaily