Category Archives: Quantum Physics
Synergy of semiempirical models and machine learning in … – American Institute of Physics
A detailed review of SEQM methods is available in the literature.4244, Figure 1(a) shows an illustration of how SEQM fits into the broader landscape of computational chemistry methodologies. It is important to note that this depiction is a simplified representation assuming the application of these methods to a hypothetical set of small molecules, such as drug-like compounds, as demonstrated in previous studies.27,45 At the lower level of accuracy, classical force fields (FFs) are employed. FFs typically utilize simple, physically motivated terms46 to account for phenomena such as bond stretching and angle bending in harmonic approximation, non-covalent interactions, and Coulomb electrostatic terms. Their computationally efficient nature enables large-scale applications, such as protein folding simulations.47 More advanced FFs incorporate additional effects, including polarization and even bond breaking/formation, as exemplified by ReaxFF.48 Machine learning interatomic potentials (MLIAPs) trained on high-quality datasets can potentially achieve greater accuracy in specific applications, such as torsional data benchmarks.27,45 Relative to traditional FFs, a typical MLIAP may contain two or three orders of magnitude more model parameters, and its numerical costs grow commensurately. MLIAP simulations of up to 107 atoms have been achieved.49,50 Both FFs and MLIAPs avoid self-consistent solutions of a quantum Hamiltonian and instead make strong assumptions regarding the spatial locality of chemical interactions, which leads to a linear scaling of computational costs with system size. We point curious readers to the comprehensive literature on MLIAPs.4,8,12,24,5153 Note, though, that the accuracy and transferability of MLIAP could not be rigorously compared with electronic structure methods, as MLIAPs are trained for specific elemental compositions and/or crystal structures, and their high accuracy is confined to the training domain. The opposite side of the scale is dominated by a family of coupled cluster (CC) approaches,54 which remain the gold standard for accurate electronic structure calculations while retaining polynomial scaling. Most other methods naturally fall in between. Spanning the space of transferability, accuracy, and cost, SEQM methods occupy the middle-ground between force fields (FFs) and Density Functional Theory Methods (DFT),55 a workhorse of computational chemistry. Much more affordable than DFT, SEQM methods are usually applied to large systems (102103 atoms), which should not, for physical reasons, be treated classically. In the recent decade, use of SEQM was substantially limited given the development of accurate and affordable DFT functionals and their highly parallelized implementations. However, we expect this balance to change with the arrival of ML-parametrized SEQM (ML-SEQM) which can offer accuracy on par with or exceeding that of DFT at much less computational cost [Fig. 1(a)]. Recent advances in ML-SEQM will be the main focus of this discussion.
The original models introduced characteristic approximations to reduce the number of electronic interactions to calculate; for example, 3- and 4- center Coulomb integrals are totally neglected in the popular Modified Neglect of Differential Overlap (MNDO) approach.41,56,57 Further on, 1-center and 2-center integrals are simplified through monopole interactions and atom-specific constants (the latter will be subjected to ML parametrization). Parameters of the model are optimized to reproduce a set of reference values and provided interatomic distances. The structural knowledge encoded in those models is simplified since it does not contain angles, bond connectivity, etc., and the final parametrization yields a single set of parameters for each element. In contrast, descriptors in ML models typically encode radial and angular information on neighboring (or even further atoms) along with atom types10,13,15,18,53 allowing a more bespoke fit. The original approach can also lead to an abundance of outliers beyond the dataset and poor transferability. As a result, any deficiencies in the reference dataset would be reflected in deficiencies in the resulting method. This statement could be easily confused with the direct quote from a modern ML paper, even though it is taken from Stewarts work published back in 2002.58 The work goes on to say, The lesson learned from this experience, an important lesson painfully learned, was that the composition of the reference dataset is of paramount importance. In 2023, this lesson may sound elementary to modern ML practitioners but it manifested the beginning of data driven techniques for quantum chemistry, and the foothold that ML has gained in the field is, therefore, no surprise. However, back in the days, outliers were tackled manually: An effective way to prevent the errors of the type that were found would have been to use rules. Such rules would likely have prevented the types of errors that are present in PM3.58 To eliminate severe outliers, SEQM was often further modified by some arbitrary rules such as additional or manually corrected terms for specific systems [water clusters, Cu liganded complexes,59 or peptide bonds as a result of improper nitrogen description,58, Fig. 1(b)]. Along with careful selection of target values (enthalpies, ionization potentials, etc.), implementation of system-specific rules implies high-level human expertise based on method development, programming, and chemical research experience. It also means that system-specific rules should be recalibrated almost by hand for new applications or chemical families. We would like to conclude this historical overview with a prediction made by Stewart himself: Finally, as more and more elements are parameterized, and as methods become increasingly sophisticated, the transition will have to be made to a purely mathematical approach.58 Stewart had foreseen that the discrepancy between chemical systems could rarely be fitted into an automated if-else conditional logic. All this goes to show that the usage of ML methods, designed to automatically identify patterns and hidden relationships in data, is in fact a highly logical direction that has been foreseen for decades.
To the best of our knowledge, the first true application of ML in SEQM could be tracked down to a 2015 report60 in which a workflow for automatic parameterization was established. Rupp et al. suggested the use of an invariant Coulomb matrix61 to take into account the structure of the molecules comprising the dataset. Given that established static parameters in orthogonalized model 2 (OM2)44 are already optimized to give the best average, this work builds upon these parameters and suggests only small structure specific corrections. The pipeline is very simple: vary one parameter P at a time to find optimal corrections P for each individual molecule using the LevenbergMarquardt algorithm;62,63 train the ML model on the derived correction P via kernel ridge regression to learn the variation of P with respect to the structure; predict P for the molecules in a test set using the ML-model; evaluate the performance of OM2 based on the P + P parameters. Figure 1(c) shows a performance comparison between the original OM2 model, a revised OM2 model (rOM2; variant conventionally reparameterized for a specific dataset in the work), and the ML-OM2 model derived with automatic parameterization in the 2015 report.60 However, rOM2 improves upon the original OM2 model, ML-OM2 exhibits slightly better accuracy for atomization enthalpies among the three models. Not only, is error distribution for ML-OM2 centered at zero, but the magnitude of errors is also noticeably reduced, narrowing the gap between SEQM and DFT. This seminal work suggests that ML is a powerful approach for a broad improvement of the SEQM family without sacrificing its favorable computational cost, even taking into account the small overhead of on-the-fly P predictions.
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Synergy of semiempirical models and machine learning in ... - American Institute of Physics
The Girlies Know: ‘Oppenheimer’ Was Actually About Us – The New York Times
From afar, the film has all the makings of a Bildungsroman, the coming-of-age form that depicts a passage from callow youth into maturity. But in Oppenheimers case, age arrived long before wisdom. A story by Murray Kempton in the December 1983 issue of Esquire describes how the real Oppenheimer was, as a precocious young man, so blessedly sheltered from the demands of real life protected from the routine troubles, discontents and worries that instruct even while they are cankering ordinary persons that he was transported to his glittering summit innocent of all the traps that every other man of affairs has grown used to well before he is 42 years old. It is only when Oppenheimer is already middle-aged, a man whose faith has only ever been in his own intelligence, that he gets his first reality check, at the hands of a once-adoring government bureaucrat named Lewis Strauss. This is an experience any self-identifying girlie will recognize: a profound betrayal from a friend-turned-frenemy.
Here the girlhood parallels move beyond the facetious to acquire a darker quality, as shame begins to erode Oppenheimers sense of self. As hes accused of being a Communist sympathizer and publicly ridiculed in a kangaroo trial, the once-venerated scientist finds each of his beliefs collapsing. The great Oppenheimer realizes that no amount of personal brilliance can counter the force of the state. He finally sees that he has devoted his intellect to a system that was rigged against him, one that took advantage of his brilliance and then punished him for it. The same man who once earnestly referred to himself as a prophet is now paralyzed by his inability to either have or act on any firm conviction; the veneer of his certainty in his own power has been stripped away. Near the films end, Oppenheimer silently reckons with visions of what his brilliance has wrought: unimaginable suffering and fire as the invention he fathered wipes out civilization itself. Even on my fourth viewing, the sight of Murphys frosty blue stare elicited in me a deep familiarity, making me recall a line from Annie Ernauxs A Girls Story: To have received the key to understanding shame does not give the power to erase it.
In theory, I have little in common with this man. But shame living with it, drowning in reminders of it, never being free from your own inadequacy and failure is a great equalizer. Being plagued by the squandering of your abilities, condemned to a lifetime of uncertainty, forever wondering where you went wrong or whether you were always set up to go wrong. This is the precondition of girlhood that Barbie tried to portray the dual shock and dissonance of navigating a world that seems to vilify your existence, imbuing it with persistent and haunting shame while also demanding that you put on a show for the hecklers. But it was while watching a helpless Oppenheimer, stunned at being forced to participate in his own public degradation by the U.S. government, that I averted my eyes in dread and recognition.
For a Great Man like him, it took the twin shames of the bombs destruction and public disgrace to have this life-altering yet basic realization about his own powerlessness. But this feeling of betrayal at the hands of the same system that once adulated you is not solely the domain of men who reach a certain age and come to the uncomfortable realization that after a lifetime of revolving around them, the world is now moving on, indifferent or even hostile to their existence. This is a rule and a warning that life has drilled into girls from age 13, if not sooner. The same powers that have displayed you like a trophy will not hesitate to spit you out the moment you have ceased to be useful.
Oppie needed greatness to understand that.
But the girlies?
We have always known.
Iva Dixit is a staff editor for the magazine. She last wrote a profile of the Jamaican dancehall star Sean Paul.
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The Girlies Know: 'Oppenheimer' Was Actually About Us - The New York Times
If Einstein and Bohr met for a beer today, what would they talk about? – Medium
Photo by Andrew George on Unsplash
The intellectual exchange between Einstein and Bohr on quantum theory remains one of the most momentous and well-documented dialogues in the history of physics.
They were two towering figures in 20th-century physics, and their debates primarily revolved around the interpretation of quantum mechanics. At the core of their disagreement were differing views on determinism, realism, and the nature of measurement in quantum systems.
Einstein was a proponent of local realism, advocating for a deterministic universe where physical properties have well-defined values independent of observation. He famously said, God does not play dice with the universe, indicating his discomfort with the inherent randomness that quantum mechanics seemed to introduce.
Bohr, on the other hand, embraced the probabilistic nature of quantum mechanics and defended the Copenhagen interpretation. According to this view, quantum systems dont have definite properties until they are measured, and the act of measurement itself plays a crucial role in determining the state of the system.
One of the most famous instances of their debate was Einsteins formulation of the EPR paradox (Einstein-Podolsky-Rosen paradox) in 1935. This thought experiment aimed to show that quantum mechanics was incomplete because it allowed for spooky action at a distance, where entangled particles could instantaneously affect each other regardless of the distance separating them. Einstein viewed this as a violation of the principle of locality.
Bohr countered by arguing that Einsteins paradox was based on classical intuitions that didnt fully apply in the quantum realm. According to Bohr, the seeming non-locality is a result of our classical expectations, and theres no violation of physical principles in the quantum description.
Given the extensive developments in quantum mechanics since their era, I cannot help but wonder how these formidable minds would converse in the context of 21st-century advances!
This article is an attempt to hypothesize their perspectives on five topics and providing an analytical account of their likely viewpoints.
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If Einstein and Bohr met for a beer today, what would they talk about? - Medium
University Assistant Predoctoral, Physics job with UNIVERSITY OF … – Times Higher Education
51 Faculty of PhysicsStartdate:01.11.2023|Working hours:30|Collective bargaining agreement:48 VwGr. B1 Grundstufe (praedoc)Limited until:31.10.2027Reference no.:1255
Do you have an interest in the foundations of quantum theory? Are you fascinated by thought experiments and do you appreciate the mathematical elegance of a physical theory? Are you interested in developing new quantum information tasks and protocols? If yes, then we invite you to join the Operational Quantum Information Team.
Your personal sphere of influence:
As a university assistant (praedoc) in this 4-year position, you will be part of the Operational Quantum Information Team around Professor Borivoje Daki, and you will be focusing on research topics in quantum foundations and quantum information theory.
Our research focuses on the foundations of quantum mechanics, quantum information theory, and practical applications of quantum information. Examples include operational reconstruction of quantum theory and quantum particle statistics, exploring quantum phenomena at macroscopic scales, and advancing quantum verification theory.
Our Team is part of the Quantum Optics, Quantum Nanophysics and Quantum Information group of the Faculty of Physics.We are member of the Vienna Center for Quantum Science and Technology (VCQ), one of the largest quantum hubs in Europe, and of the Austrian Cluster of Excellence (quantA), advancing basic research in quantum sciences, aiming to expand the frontiers of knowledge and thus being the engine for future innovations.
You will also benefit from being fellow of the Vienna Doctoral School in Physics (VDSP), being part of a thriving community with more than 100 quantum scientists on premise, about 300 quantum researchers in Vienna.
The Daki group is an international team of eight young scientists (Master & PhD). Our expertise lies in quantum foundations and quantum information theory.
Your future tasks:
You will actively participate in research, teaching & administration. This means:
This is part of your personality:
What we offer:
Inspiring working atmosphere:You are a part of an international academic team in a healthy and fair working environment.
Good public transport connections:Your workplace in the center of beautiful Vienna is easily accessible by public transport.
Potential for development:Success in life depends on what you make of it, but if you are ambitious and successful, there are plenty of opportunities to connect you to all relevant top research groups in the world.
Internal further training & Coaching:The Vienna Doctoral School as well as the department of human resources offer plenty of opportunities to grow your skills in over 600 courses to choose from free of charge.
Fair salary:The basic salary of EUR 2.457,00 (30h, 14x p.a.) increases if we can credit professional experience.The employment duration is 4 years. Initially limited to 1.5 years, the employment relationship is automatically extended to4 yearsif the employer does not terminate it within the first 12 months by submitting a non-extension declaration.
Equal opportunities for everyone:We look forward to diverse personalities in the team!
t is that easy to apply:
Note, that while a Masters degree is the usual legal prerequisite for a PhD position at the University of Vienna, we can consider Bachelors (preferentially with Honors) in exceptional cases, too.
If you have any questions, please contact:
Borivoje Dakicborivoje.dakic@univie.ac.at
We look forward to new personalities in our team!The University of Vienna has an anti-discriminatory employment policy and attaches great importance to equal opportunities, theadvancement of womenanddiversity. We lay special emphasis on increasing the number of women in senior and in academic positions among the academic and general university staff and therefore expressly encourage qualified women to apply. Given equal qualifications, preference will be given to female candidates.
University of Vienna. Space for personalities. Since 1365.
Data protection
Application deadline:10/06/2023
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University Assistant Predoctoral, Physics job with UNIVERSITY OF ... - Times Higher Education
New Horizon Prize in Physics awarded to scientists chasing … – Livescience.com
Two scientists have won a $100,000 prize for describing both the structure and a way to detect mysterious black hole photon spheres. These enigmatic structures form at the edges of black holes, and could reveal the underlying physics that govern the most extreme objects in the cosmos.
Alexandru Lupsasca, of Vanderbilt University, and Michael Johnson, of Harvard University, won the New Horizon Prize in Physics "for elucidating the sub-structure and universal characteristics of black hole photon rings, and their proposed detection by next-generation interferometric experiments."
The New Horizons award is given each year to early career researchers by the Breakthrough Prize Foundation, and the prize money is donated by tech billionaires Sergey Brin, Priscilla Chan and Mark Zuckerberg, Yuri and Julia Milner, and Anne Wojcicki. A second prize was also awarded this year to Mikhail Ivanov, of MIT, Oliver Philcox, of Columbia University and the Simons Foundation, and Marko Simonovi, of the University of Florence for their work on the universe's 'cosmological collider'.
When photons stream toward a black hole, most are either bent away or (if they cross its event horizon) engulfed permanently in the dark abyss. Yet some rare light particles avoid this fate instead they surf the cosmic monster's gaping mouth in a series of tight orbits and, if the black hole is spinning, steal some of its rotational energy to miraculously spring free.
Related: The closest black holes to Earth may be 10 times closer than we thought
Detecting these photons for the first time would give physicists unprecedented insight into the most extreme objects in our universe, as well as how the known laws of physics break down in the presence of their infinite gravitational pulls.
"Gravity is the big mystery. To date we don't know how to combine Einstein's theory of general relativity, which is the relativistic picture of gravity as the bending of space-time, with quantum mechanics," the theory of the very small, Alexandru Lupsasca, who used relativity to devise what the rings should look like and find the parameters that describe them, told Live Science.
"The problem is that gravity is very weak it's the weakest of all forces," Lupsasca said. "So to have a chance of understanding quantum gravity, we have to look where gravity is strongest. And nowhere is gravity stronger than around a black hole."
Supermassive black holes are enormous, measuring roughly the width of the solar system, so it can take a photon around six days travelling at the speed of light to make an orbit. At the end of these six days, photons can either perform a U-turn to make another orbit, or fly into or away from the black hole. The photons that slip a black hole's gravity emerge in the form of an ultrathin halo around the pure black chasm: a photon sphere.
Photon spheres can be broken down into even smaller rings, with the light that went in last nesting in near-infinite bands inside the light that went in first. Peeling back these layers would reveal a string of snapshots displaying every angle of the surrounding universe, beginning with the recent past and running all the way back to the scant remaining glimmers of light captured eons ago by the black hole.
"It's like a laundromat, it takes light from every angle, lets it tumble and shoots it off in every direction," Lupsasca said. At any given time, only some photons can fit: "there's always more photons coming in, but there's always some leaking out."
After making theoretical predictions of what the rings should look like, the pair and their colleagues set about devising ways to measure the halos. Johnson realized that the Event Horizon Telescope (the EHT, which he and other researchers had used to capture the first-ever image of a black hole) was perfect for this task, if only the photon sphere could be distinguished from the fuzzy band of other light streaming from the black hole.
To achieve this, Johnson reasoned, researchers would only need to place the EHT into an array with one more telescope to distinguish the first band of the photon sphere.
"The miracle is that and this is unlike anything we've ever studied in astronomy that you can add one orbiter that's enough to study the photon ring," Johnson told Live Science. "That was just a complete shock."
Lupsasca and Johnson are working on a pitch to have NASA launch a satellite carrying the extra telescope. If successful, they could obtain the very first image of the outer band of a photon sphere within 10 to 15 years. Doing so would enable them not only to judge the size of a black hole's event horizon and its spin but also, once they have measured a second band, to probe some of the most radical theories in physics.
"This photon ring comes from as close as you can see to the visible edge of the observable universe," Lupsasca said. "If that's not enough to get you excited, I don't know what gets you out of bed."
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New Horizon Prize in Physics awarded to scientists chasing ... - Livescience.com
Theory of all matter physicists among 2023 Breakthrough prize winners – The Guardian
Science prizes
Immunologists behind pioneering cancer therapy also among recipients of most lucrative prize in science
Thu 14 Sep 2023 09.00 EDT
Two physicists who played a key role in advancing a theory that describes the basis of all matter and a pair of immunologists who developed a pioneering cancer therapy that is currently being investigated as a treatment for autoimmune disease are among the winners of the most lucrative prize in science.
Founded in 2012, the Breakthrough prize is the worlds largest international science prize, with the winners of the five main awards three in life sciences, one in fundamental physics, and one in mathematics each receiving a $3m (2.4m) prize
Prof John Cardy, an emeritus fellow at the University of Oxford, shares this years physics prize with Alexander Zamolodchikov for their contributions to statistical physics and quantum field theory a theoretical framework that describes how different states of matter may be described by fluctuating fields, analogous to magnetic and electric fields.
The mathematical formulas they developed and ideas they have advanced have improved scientific understanding of the properties of different materials and how they transition between different states, as well as predicting how they are likely to behave in different circumstances, with far-reaching applications in various branches of physics and mathematics, from black holes to superconductors.
They also help to give us an understanding of the dynamical processes that may be going on in things like quantum entanglement, which is very important for quantum computing, Cardy said.
A former mountaineer and a keen oil painter, Cardy said an appreciation of beauty underpinned all of his interests, whether that was the beauty of mountains or of mathematical equations. Its an idea thats very important to me, he said.
Among the winners of the prizes for life sciences are Carl June and Michel Sadelain, who pioneered the development of genetically engineered immune cells designed to recognise and destroy an individuals cancer. Known as Car T-cells, these living drugs are being investigated as a potential treatment for severe lupus, an autoimmune disease that can cause life-threatening damage to the heart, lungs, brain and kidneys.
Sadelain said the idea of giving T-cells an intelligence boost by genetically instructing them about which cells to target had first occurred to him as a PhD student, based on the realisation that vaccines arent always efficacious, theyre not always fast enough, and above all in cancer, theyre not strong enough to overcome the cancer.
To me [current Car T-cells] are a prototype for what I hope will be a large family of medicines that we call living drugs. They are immune cells that are genetically targeted and programmed to perform a task of our choosing, he said.
Also taking prizes for life sciences are a team that has played a key role in unpicking the genetics of Parkinsons disease and a trio of scientists based at Vertex Pharmaceuticals in Massachusetts, US, who identified a combination of drugs that repair the defective chloride channel protein in patients with cystic fibrosis.
Prof Andrew Singleton, whose discovery that mutations in a gene called LRRK2 underpin some of the neuronal damage that occurs in patients with Parkinsons, described himself as an optimist who had always been driven by the belief that his research would someday lead to a treatment even if he was wrong 99.9% of the time. A drug that targets the LRRK2 protein is being tested in late stage clinical trials.
The mathematics prize went to Prof Simon Brendle at Columbia University in New York for his transformative contributions to differential geometry a discipline that studies the geometry of smooth shapes and spaces.
The work of these laureates is very impressive whether its exploring abstract ideas or unraveling the causes of human diseases and producing effective treatments that impact millions of lives, said Priscilla Chan and Mark Zuckerberg, two of the founding sponsors of the Breakthrough prize.
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Theory of all matter physicists among 2023 Breakthrough prize winners - The Guardian
Spreading Hope and Saving Lives: Michael Tanner’s Urgent … – WAOK
Suicide Prevention Awareness Month is a time to shed light on a sensitive but critically important issue suicide prevention. Recently, licensed marriage and family therapist, Michael Tanner, took his message to The Rashad Richey Morning Show, where he emphasized the urgency of addressing the mental health crisis and saving lives.
Suicide Prevention Awareness Month serves as a vital platform to bring attention to the devastating impact of suicide. By raising awareness and reducing stigmas surrounding mental health, we can create a more compassionate society, ultimately saving lives.
As a licensed marriage and family therapist, Mr. Tanner brings a wealth of knowledge and expertise to the field of mental health. With an unwavering dedication to suicide prevention and promoting mental health, he serves as a powerful advocate for those who may be struggling.
During the interview with Rashad Richey, Mr. Tanner highlighted several key points. He stressed the importance of recognizing warning signs that someone may be contemplating suicide and the urgency of taking action to provide support. By listening, offering compassion, and connecting individuals in need to appropriate resources, lives can be saved.
Michael Tanner's urgent message on suicide prevention is a call-to-action for all. By spreading awareness, offering support, and promoting mental health education, we have the power to save lives. Let us join forces during Suicide Prevention Awareness Month and make a difference within our communities. Together, we can provide hope and support to those who need it most. To listen to the entire conversation, download the audio above.
Dr. Rashad Richey, host of the award-winning Rashad Richey Morning Show on News & Talk 1380 WAOK/V-103FM (HD3) (Weekdays 7am -10am), and the Dr. Rashad Richey Review on SiriusXMs Urban View (Sundays at 1pm and 9pm), was voted 'Best Talk Radio Personality in Atlanta' by readers of the Atlanta Journal-Constitution and named 'Most Trusted Voice in Atlanta' by the Atlanta Business Journal, making him the first African-American to receive these distinctions.
The intelligent and fearless television news anchor for the opinion news show, 'Indisputable with Dr. Rashad Richey on the TYT Network, which was named 'fastest growing TV news show in America', and Political Commentator for The People's Station V-103 FM, America's largest urban station, also serves as President of Rolling Out, the largest free-print urban publication in the country. This multimedia powerhouse with over 3-million combined subscribers/followers on Facebook Watch, YouTube, Podcasts, and Twitch combined, is a noted multidisciplinary academic scholar and university professor/lecturer and an Emmy-nominated television Political Analyst for CBS News Atlanta.
Believing in the power of knowledge and education, Dr. Richey holds several advanced degrees, making him one of the most academically credentialed individuals in American history according to America News Now. Completing doctoral research studies in federal policy reform from Clark Atlanta University, Dr. Richey also holds a PhD from the Business University of Costa Rica where his research and doctoral dissertation highlighted the nuances and intersectionality of politics, policy and religion.
Being a student of leadership, Dr. Richey completed studies in Executive Leadership at Cornell University and was accepted into a specialty executive law program at Harvard University in International Finance: Policy, Regulation, and Transactions. Understanding the connectivity of culture and science, Dr. Richey earned his Master of Science in Neuroscience from the University of Pacific, where his masters thesis researched cognitive functionalities of brain entrainment. Dr. Richey also completed a Master of Science in Applied Physics and Quantum Mechanics from Universidad Empresarial, his masters thesis was adapted into a book titled, Ancient Egyptian Mastery of Quantum Physics, Vibratory Frequency, and Geometric Sciences: An Overview of Complex Scientific Applications in Ancient Cultures, which quickly became the #1 Physics, #1 Science, #1 History, and #1 Egyptian Genre b0ok on the Amazon platform.
As an executive leader, Dr. Richey says its imperative to combine business practices with compassionate leadership principles, which was a primary focus when completing his Master of Business Administration (MBA) program at Beulah Heights University. Dr. Richey also holds a Master of Laws (LL.M) in Humanitarian Studies from the University of Renaissance and a Doctor of Law in International Law (ABD) from the research institution, Azteca University.
He is currently in the final leg of completing his Juris Doctor (Law Degree) from Birmingham Law School and dually enrolled in a PhD in Quantum Physics program, which is a collaborative between the Clark Atlanta University physics department and the School of Life Information Science & Engineering at Asia Pacific School of Business.
As host of The Rashad Richey Morning Show, Dr. Richey has interviewed everyone from Vice-President Kamala Harris to TI, and always brings relevant information, the best on-air debates, and most insightful interviews in media. Tune in every weekday morning from 7am-10am on News and Talk 1380-WAOK, V-103FM (HD3),www.WAOK.com, or on the Audacy App.
He is currently in the final leg of completing his Juris Doctor (Law Degree) from Birmingham Law School and dually enrolled in a PhD in Quantum Physics program, which is a collaborative between the Clark Atlanta University physics department and the School of Life Information Science & Engineering at Asia Pacific School of Business.
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Spreading Hope and Saving Lives: Michael Tanner's Urgent ... - WAOK
Scalable multipartite entanglement achieved with ultracold atoms in optical lattice – Phys.org
This article has been reviewed according to ScienceX's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility:
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by Chen Yehong , University of Science and Technology of China
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Researchers from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS), in collaboration with researchers from Tsinghua University, led by Ma Xiongfeng, and Fudan University, led by Zhou You, have achieved significant advancements in the preparation and measurement of scalable multipartite entangled states.
Using ultra-cold atoms trapped in optical lattices, the research team successfully prepared multi-atom entangled states by creating a two-dimensional atomic array, generating entangled atom qubit pairs, and sequentially connecting these entangled pairs. Their work is published in Physical Review Letters.
The American Physical Society also highlighted this achievement with a feature in Physics Magazine titled "Milestone for Optical-Lattice Quantum Computer."
Quantum entanglement is fundamental phenomenon underlying quantum computing, the capabilities of which grow exponentially with the increase in the number of entangled qubits. Therefore, the preparation, measurement and coherent manipulation of large-scale entangled states are central challenges in the field of quantum research.
Among the physical systems used to implement quantum bits (qubits), ultracold atomic qubits in optical lattices exhibit excellent coherence, scalability and high-precision quantum control, which position them as an ideal choice for carrying out quantum information processing.
Since 2010, the USTC research team has systematically studied multibody phase transitions, atomic interactions and entropy distribution dynamics in optical lattices.
By 2020, the team achieved an entanglement fidelity of 99.3% with over 1,000 pairs of entangled atoms. These studies have paved the way for enhancing the fidelity of atomic entanglement and the capability of parallel atomic control, laying the foundation for larger multi-atom entangled states and further quantum computing research. However, previous efforts faced bottlenecks due to the limited ability to control individual atomic qubits, significant phase shifts in optical lattices, and a lack of effective methods for detecting and controlling multi-atom entanglement states.
To overcome these technical challenges, the team led by Pan Jianwei and Yuan Zhensheng developed a new equal-arm, cross-beam interference and spin-dependent superlattice system. They integrated self-developed single-lattice resolution, wide-band achromatic quantum gas microscopy and multiple sets of digital micromirrors for spot shape editing. This setup allowed for both multi-atom global parallel and local single grid point measurement and control.
With this, they achieved a 99.2% filling rate of a two-dimensional atomic array and prepared entangled Bell states with an average fidelity of 95.6% and a lifespan of 2.2 seconds. Furthermore, they connected adjacent entangled pairs to prepare a 10-atom one-dimensional entangled chain and an eight-atom two-dimensional entangled block.
This work marks a significant step toward large-scale quantum computation and simulation using optical lattices.
More information: Wei-Yong Zhang et al, Scalable Multipartite Entanglement Created by Spin Exchange in an Optical Lattice, Physical Review Letters (2023). DOI: 10.1103/PhysRevLett.131.073401
Journal information: Physical Review Letters
Provided by University of Science and Technology of China
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Scalable multipartite entanglement achieved with ultracold atoms in optical lattice - Phys.org
Higher harmonics and supercontinuum generated from the Kerr … – Nature.com
Following Kerr21, Buckingham22, 23, Duguay28, and Alfano et al.1, 4, the general form for the index of refraction based on the index of refraction becomes electric field E dependent:
$$n= {n}_{0 }+ {n}_{2}{E(t)}^{2},$$
(1)
where n0 is the index of refraction, n2 is the nonlinear index from various mechanisms, and E is the electric field. Our ansatz is that the index of refraction (n) is a function of angular frequency () and time (t): n(,t).
In the EM model, the Kerr index of refraction n2 of the material depends on the time response of the underlying mechanisms of the material to the electric field of the laser:({n}_{2}= sum_{i}{n}_{i}), where i=mechanisms (such as electronic (~1017s), molecular redistribution (~1014s), plasma (~1013s), rotational (~1012s), librational, and other slower mechanism)28,29,30,31,32. The work of KenneyWallace showed the various temporal components of the Kerr index in CS231, 32.
Based on the Kerr effect, the electric field of the light is distorted in the CEP after an intense light beam propagates a distance z into the material and the electric field of the light has the form:
$$begin{aligned} Eleft( {t,omega } right) = & E_{0} e^{{ - frac{{t^{2} }}{{T^{2} }}}} cosleft[ {phi left( {t,omega } right)} right] \ = & E_{0} e^{{ - frac{{t^{2} }}{{T^{2} }}}} cosleft[ {omega _{0} t - kz + varphi } right], \ end{aligned}$$
(2)
where the exponential time is T = (frac{{tau }_{p}}{sqrt{2mathrm{ln}2}}); p is the full width half maximum (FWHM) of the pulse; and the bracket is the phase (upphi left(mathrm{t},omega right).) The phase (upphi left(mathrm{t},omega right)) is modulated by the index of refraction due to Kerr effect. The high laser intensity induces changes in the refractive index from electronic and molecular distortion. The propagation constant becomes time and frequency dependent: (k=frac{nomega }{c}). Expanding about ({upomega }_{0}), the modulated instantaneous phase of Carrier Envelope Phase (CEP) under the envelope becomes:
$$phi left(t,omega right)= {omega }_{0}left{t-frac{nleft(t,omega right)z}{c}right}+varphi ,$$
(3)
where ({upomega }_{0}) is the central angular frequency of the laser, n(t,) is the refractive index, z is the propagating distance, and is the offset phase (set (varphi =0)). This phase is the key for the generation of the Supercontinuum and Higher Harmonics where the response time of the materials index of refraction is critical to the generation of HHG. The offset CEP phase is set to be zero for the cosine-like pulse which drives HHG modes. The nonlinear refractive index with quadratic field dependence and the material response time is given by:
$$nleft(tright)={n}_{0}+{int }_{-infty }^{t}{int }_{-infty }^{t}fleft({t}{prime},{t}^{{prime}{prime}}right)Eleft(t-{t}{prime}right)Eleft(t-{t}^{{prime}{prime}}right)d{t}{prime}d{t}^{{prime}{prime}},$$
(4)
where n0 is the ordinary index, E the electric field and,
$$fleft({t}{prime},{t}^{{prime}{prime}}right)=left(frac{{n}_{2}}{tau }right){e}^{- frac{{t}{prime}}{tau }} delta left(t-{t}^{{prime}{prime}}right).$$
(5)
Here, n2 is the nonlinear index and is the response time (tau). Equation(4) may be simplified to:
$$nleft(tright)= {n}_{0}+ left(frac{{n}_{2}}{tau }right){int }_{-infty }^{t}{e}^{- frac{left(t-{t}{prime}right)}{tau }}{E}^{2}left({t}{prime}right)d{t}{prime}.$$
(6)
The pure electronic mechanism of n2 is the instantaneous index of refraction for rare noble gases like Ar, Kr, and Ne and solids involving no translation of nuclei or rotation of atomic cluster. It is expected to have relaxation response time much less than the optical period (<<(frac{1}{{omega }_{0}})), faster than few femtoseconds. For this case, the index n(t) responses to E(t) at optical frequencies. Hence the weighting function ((frac{1}{tau }){e}^{- frac{left(t-{t}{prime}right)}{tau }}) may be replaced by (updelta left(mathrm{t}-{mathrm{t}}^{mathrm{^{prime}}}right)). Following the Kerr effect, the electronic response of the instantaneous response time on 50fs nonlinear index for ultrafast laser pulses causes the HHG and responsible for ESPM to become:
$${n}_{instantaneous}(t)={n}_{0}+{n}_{2}{[{E}_{0}{e}^{- frac{{t}^{2}}{{T}^{2}}}cosphi left(tright)]}^{2}.$$
(7)
Equation(7) represents the instantaneous response of the index of refraction. This is the ansatz that has been used before in the form of n by luminaries like Kerr21 and Buckingham22. The ansatz n(t) follows the modulation optical cycles of the phase of E. The instantaneous response is used to follow the optical cycle rather than the envelope of the CEP without time averaging was proposed by Buckingham22. On the other hand, the average index of refraction
The general form for the nonlinear refractive index with quadratic field dependence is,
$$nleft(tright)={n}_{0}+delta n= {n}_{0}+ {int }_{-infty }^{t}f({t}{prime},t){E}^{2}left({t}{prime}right)d{t}{prime},$$
(8)
where n0 is the normal index, E(t) is the laser electric field assumed to have a Gaussian envelope (({E}_{0}left(tright)={E}_{0}{e}^{-frac{{t}^{2}}{{T}^{2}}})) and f(t) is the weighting function describing the response of the system; f(t) assumes the form (frac{{e}^{-frac{t}{T}}}{tau }) where is the response time of the material. The incident lasers electric field has the form given by Eq.(2). Following the ESPM model for the electric field E(t) gives:
$$Eleft(tright)={E}_{0}{e}^{- frac{{t}^{2}}{{T}^{2}}}cosleft(omega t-frac{omega nleft(tright)z}{c}right),$$
(9)
with the instantaneous n(t):
$$nleft(tright)={n}_{0}+{n}_{2}{[{E}_{0}{e}^{- frac{{t}^{2}}{{T}^{2}}}cosleft({omega }_{0}tright)]}^{2}.$$
(10)
Using an averaging procedure on n(t) to simulate the generation of the signal caused by the material response resulting in HHG and the associated characteristics that can be found in the experimental results such as the number of odd harmonics and the cutoff frequency.
We have numerically applied an averaging procedure using response filter to the n(t) for the Kerr effect in different media:
$$
(11)
to generate HHG and SC for the instantaneous electronic cloud response time on about 50 as; the fast response time of ionization and molecular redistribution on about 1fs; and the slower rotational and vibrational relaxation times of 110ps or greater for different pulse durations.
After substituting Eq.(11),
$$Sleft(omega right)=frac{c}{4pi }{left|E(omega )right|}^{2},$$
(12)
where E() is the Fourier transform of E(t).
For a material with response time slower than pure electronic on the order of such as molecular redistribution, plasma, librational, orientational, and vibrational motion ((t>tau >frac{10}{{omega }_{L}})), the envelope of the pulse is reflected in n(t) and no HHG is produced. For slow response time of the material , the average n(t) becomes the classical SPM following the envelope of the pulse:
$${n}_{slow}left(tright)={n}_{0}+frac{{n}_{2}}{2}{left[{E}_{0}{e}^{- frac{{t}^{2}}{{T}^{2}}}right]}^{2}.$$
(13)
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Neutrino-Photon Interactions: Unlocking the Mysteries of Particle … – SciTechDaily
New research has discovered new interactions between neutrinos and photons, potentially shedding light on mysteries in particle physics and solar phenomena.
Elusive fundamental particles called neutrinos are predicted to interact unexpectedly with photons under extreme conditions.
Research at Hokkaido University has revealed that elusive particles called neutrinos can interact with photons, the fundamental particles of light and other electromagnetic radiation, in ways not previously detected. The findings from Kenzo Ishikawa, Professor Emeritus at Hokkaido University, with colleague Yutaka Tobita, lecturer at Hokkaido University of Science, were published in the journal Physics Open.
Our results are important for understanding the quantum mechanical interactions of some of the most fundamental particles of matter, says Ishikawa. They may also help reveal details of currently poorly understood phenomena in the sun and other stars.
Neutrinos are one of the most mysterious fundamental particles of matter. They are extremely difficult to study because they barely interact at all with other particles. They are electrically neutral and have almost no mass. Yet they are highly abundant, with vast numbers constantly streaming from the sun and passing through the Earth, and indeed ourselves, with barely any effect. Learning more about neutrinos is important for testing and perhaps refining our current understanding of particle physics, known as The Standard Model.
A total solar eclipse, with the solar corona visible.
Under normal classical conditions, neutrinos will not interact with photons, explains Ishikawa We have revealed, however, how neutrinos and photons can be induced to interact in the uniform magnetic fields of the extremely large scaleas large as 103 kmfound in the form of matter known as plasma, which occurs around stars. Plasma is an ionized gas, meaning that all of its atoms have acquired either an excess or a deficiency of electrons, making them negatively or positively charged ions, rather than the neutral atoms that can occur under everyday conditions on Earth.
The interaction described by the researchers involves a theoretical phenomenon called the electroweak Hall effect. This is an interaction of electricity and magnetism under extreme conditions where two of the fundamental forces of naturethe electromagnetic and the weak forcesmerge into the electro-weak force. It is a theoretical concept, expected to apply only in the very high energy conditions of the early universe or within collisions in particle accelerators.
The research has derived a mathematical description of this unexpected neutrino-photon interaction, known as the Lagrangian. This describes everything known about the energy states of the system.
Kenzo Ishikawa, first and corresponding author of the study. Credit: Sohail Keegan Pinto
In addition to its contribution to our understanding of fundamental physics, our work might also help explain something called the solar corona heating puzzle, says Ishikawa. This is a long-standing mystery concerning the mechanism by which the outermost atmosphere of the sunits coronais at a much higher temperature than the suns surface. Our work shows that the interaction between neutrinos and photons liberates energy that heats up the solar corona.
In concluding remarks, Ishikawa expressed their teams aspiration: We now hope to continue our work in search of deeper insights, especially in connection with energy transfer between neutrinos and photons under these extreme conditions.
Reference: Topological interaction of neutrino with photon in a magnetic field Electroweak Hall effect by Kenzo Ishikawa and Yutaka Tobita, 12 August 2023, Physics Open.DOI: 10.1016/j.physo.2023.100174
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Neutrino-Photon Interactions: Unlocking the Mysteries of Particle ... - SciTechDaily