Category Archives: Quantum Physics
Waterloo welcomes three Banting Fellowship recipients | Waterloo … – The Iron Warrior
As the University of Waterloo launches its annual National Postdoc Appreciation Week (NPAW), we celebratethreeWaterloo postdoctoral scholars have been awarded the Banting Postdoctoral Fellowship, as announced on Tuesday, August 29.
The Banting Postdoctoral Fellowships program provides funding to the very best postdoctoral applicants, both nationally and internationally, who will positively contribute to the countrys economic, social and researchbased growth.
Across Canada, 70 researchers will receive $70,000 for two years, with a total of $9.8 million awarded nationally.
The Banting Postdoctoral Fellowships support transformative research that can advance our understanding of emergent fields and address global challenges, says Dr. Jeff Casello, associate vice-president of graduate studies and postdoctoral affairs. We are thrilled to welcome these new scholars to our community.
The University of Waterloo attracts world-class postdoctoral scholars who transform and disrupt the status quo and we are always delighted to support them as they continue to pursue personal and professional goals that will have positive impacts on Canadian societys future.
We are excited to have these emerging scholars join the Faculty of Science, says Dr. Chris Houser, dean of the Faculty of Science. Their transformational research pushes the boundaries of knowledge and imagination from microbial reactions to distant galaxies, and I look forward to learning the outcomes of their research.
Meet this years Banting Fellowship recipients:
Joshua Foos Banting-funded research project is titled Understanding the quantum physics of spacetime. The twin discoveries of quantum mechanics and Einstein's theory of general relativity (our best theory of gravity) in the early twentieth century revolutionized the landscape of modern physics, giving us accurate predictions about physical phenomena from the subatomic level all the way to astronomical scales. However, combining the two theories has presented a historically difficult problem for physicists.
Dr. Foo will be working with Professor Robert Mann on a project that focuses on how to describe quantum-gravitational effects that are expected to emerge when we treat objects in general relativity (for example: black holes) as possessing quantum-mechanical properties, such as the ability to be in a superposition of two places at once.
These descriptions, in turn, will allow me to develop experimental tests that can detect the quantum features of gravity, Foo says.
The study of such systems will deepen our fundamental understanding of space and time at the quantum level and bring us closer to constructing a quantum theory of gravity. Foos research is well-placed within the broad cultural curiosity surrounding our century-long quest for a unified theory.
Ian Roberts is working with Professor Michael Hudson on a project titled Star formation quenching in galaxy clusters. We learn from Roberts project that galaxies in the universe inhabit a range of environments. Such environments span from the low densities of isolated galaxies in the field through to the extremely high galaxy densities found in galaxy clusters.
Thanks to modern astronomical surveys of millions of nearby galaxies, we now know that galaxies in high-density environments (such as clusters) tend to form far fewer stars than galaxies which are isolated in the field. This reduction in star formation is referred to as quenching.
Roberts research will address the following question: Which physical processes in clusters are responsible for quenching galaxy star formation? Specifically, Roberts will explore how the fuel for the formation of new stars (cold atomic and molecular hydrogen gas) can be removed from galaxies as they orbit around their host cluster. This removal of the fuel for star formation can in turn quench galaxies in dense environments.
This research project will make important contributions to our understanding of the process of star formation (the life of galaxies) and the eventual star formation quenching (the death of galaxies) in galaxy clusters.
Saraswati will work alongside Professor Philippe Van Cappellen on their research project titled Will rewetting Canadas degraded peatlands help mitigate climate warming? Dr. Saraswati working with Professor Philippe Van Cappellen on the project. Many countries, including Canada, have proposed and already implemented the rewetting of drained peatlands as a Nature-based Solution (NbS) to curb climate warming caused by greenhouse gas (GHG) emissions. However, whether this NbS is an effective climate change mitigation strategy remains controversial.
Only a small number of field-based GHG flux studies have clearly shown a reduction of carbon dioxide emissions from rewetted peatlands, while at the same time, providing evidence for increasing methane emissions.
The latter is worrisome because methane has a much higher radiative forcing efficiency than carbon dioxide. Emissions of GHGs from peatlands are intimately linked to the turnover of organic carbon by the resident soil microbial communities, Saraswati says.
This is why a quantitative understanding of the complex, microbially mediated reaction network underlying soil organic matter (SOM) decomposition is central to explaining the response of carbon dioxide and methane emissions from peatlands to rewetting. The functioning of this reaction network depends on the energetics of the various chemical transformation pathways involved, for example, how much energy is consumed or released as a given reaction proceeds.
Saraswatis research will use microcalorimetry to directly measure the energetic yields of reaction pathways that produce carbon dioxide and methane during SOM decomposition. A key outcome of this research will be microcalorimetric assays to quantitatively assess the degradability of SOM that will be used as input to a novel, bioenergetics-informed reaction network model of SOM decomposition.
The latter will then replace the current oversimplistic SOM reaction module in the Canadian Model for Peatlands, used for Canadas national greenhouse gas reporting and prediction.
The best and brightest are drawn to Waterloo, as evidenced by three outstanding postdoctoral researchers joining the University to pursue their Banting Postdoctoral Fellowship. Our diverse postdoctoral research community supports each other to develop academically, professionally, and personally within a collaborative environment that prioritizes well-being, growth and achievement.
Institutionally, we are also pleased to present Waterloo-specific funding opportunities:
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Waterloo welcomes three Banting Fellowship recipients | Waterloo ... - The Iron Warrior
Book Review: The Lights, by Ben Lerner – The New York Times
But the speaker of The Lights turns out to be many speakers, one of whom cant help shaking his head at the literary pretensions of an earlier self:
I am trying to remember what it felt like to believedisjunction, non sequitur, injectionbetween sentences might constitutemeaningful struggle against the empiretyping away in my dorm.
The speaker of another poem, The Camperdown Elm, never left that dorm rooms story line; this alternate identity continues to make an art of discontinuity in the present:
Our children do not meanTheir numbers are up, the firefliesTo kill them when they cupAround the soft bodies, lightMusic softens featuresThe way a mild solventSoftens the acrylic, yellowing in time.
The multiple literary personalities of The Lights carry on an internal debate tournament about what poems ought to do or be. Part of me wants to say there is a mock-oratorical mode capable of vitalizing critical agency, Lerner writes, and part of me/wants to praise the maples winged samaras. Toward the books conclusion, he dreams up yet another kind of poem and struggle against empire to come:
All I need my song to one day say is you are my princess and my father and youre breathing glass, soft glass that links you, that rain outside of time is mist, is glass, and I want you to fan out and take the bridges.
Walt Whitman once claimed to contain multitudes. Lerners lucid dreamer wants a song that will mobilize those multitudes. Whitman makes multiple appearances throughout The Lights; in homage to the poet of internal contradictions, Lerner reads Crossing Brooklyn Ferry as an artwork that never quite closes the gap between heaven and earth: Its among the greatest poems and fails/because it wants to become real and can/only become prose. If only for a moment, Whitmans poem, like poetry writ large, wants to become real and can, when you read between Lerners lines.
Character is another word for typographical symbols like / or i. Symbol and character, verse and conversation, song and story coexist in the prose/poems of The Lights. Lerner populates his poetry with fictions like Emma, Rose, Marcela, Luca, Ari, Bob Lolly and Ben. Some of his speakers have no names and others, many. They tell stories, console one another and depart like visitors in a dream. A politician advises scientists to hit the body/with a tremendous, whether its ultraviolet/or just very powerful light; when you look into the box, a recovering meth addict explains of quantum physics, the cat is supposed to be alive or dead, not alive and dead; a child insists the book tucked under her pillow at bedtime will help me dream.
It takes a poet to invent characters who argue that the voice must be sung into existence. It takes a novelist to honor so many perspectives, histories and intimacies in one book. Which of us, in his moments of ambition, has not dreamed of the miracle of a poetic prose? Charles Baudelaire asked over a century ago. The poet/novelist of The Lights enlarges Baudelaires experiments in prose poetry into a multistory dream house for contemporary American readers.
An oblique stroke divides life into either/or, but it can also conjoin things as an inclusive and: poet/novelist, symbol/character. The Lights" reminds us that we are one and many: princess and father, everyone in the dream and glass, soft glass bending in long meadows.
Princess/father/everyone/glass. You could go on like this forever.
Srikanth Reddy teaches at the University of Chicago and is poetry editor of The Paris Review. His most recent book is Underworld Lit.
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Experiments Support Theory for Exotic Kagome States – Physics
September 15, 2023• Physics 16, s135
The observation of Fermi pockets in the Fermi surface of exotic superconductors provides a major step toward explaining some mysterious electronic states.
One of the goals of condensed-matter physicists is to catalog and explain the wide array of electronic states that can appear in materials, improving researchers understanding of important phenomena such as superconductivity. In recent years, experimentalists have discovered several unexpected exotic electronic states in materials called kagome superconductors, prompting intense debate over the nature of these states. Now Ilija Zeljkovic of Boston College and his colleagues have discovered features in the band structures of these materials that point toward an explanation [1].
The kagome family of superconductors have lattices with sixfold rotational symmetry and transition at temperatures of 70100 K to a so-called charge-density wave (CDW) statea state with a periodically modulated charge density. Theorists have explanations for this CDW state but not for several other CDW and Cooper-pair-density wave states that have lower transition temperatures. A theory published last year proposed that small features in the materials Fermi surfaces known as Fermi pockets could be associated with the high-temperature CDW and could also generate the unexplained states through standard mechanisms [2]. But until now, no one had observed these features unambiguously.
Zeljkovic and his colleagues have imaged these pockets in three kagome superconductors. The researchers show that the pockets link to both the high-temperature, parent CDW state and to two of the lower-temperature states. These results provide the first experimental evidence supporting the theory involving Fermi pockets.
David Ehrenstein
David Ehrenstein is a Senior Editor for PhysicsMagazine.
Hong Li, Dongjin Oh, Mingu Kang, He Zhao, Brenden R. Ortiz, Yuzki Oey, Shiang Fang, Zheng Ren, Chris Jozwiak, Aaron Bostwick, Eli Rotenberg, JosephG. Checkelsky, Ziqiang Wang, StephenD. Wilson, Riccardo Comin, and Ilija Zeljkovic
Phys. Rev. X 13, 031030 (2023)
Published September 15, 2023
A demonstration that certain electron-transport processes can be tuned in a hybrid semiconductor-superconductor system could be useful for developing quantum computers. Read More
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Experiments Support Theory for Exotic Kagome States - Physics
0.000000000000000005 Seconds Physicists Generate One of the Shortest Signals Ever Produced by Humans – SciTechDaily
Scientists from the University of Konstanz developed a method using femtosecond light flashes to generate electron pulses with a duration of around five attoseconds. This breakthrough, offering a higher time resolution than light waves, paves the way for observing ultrafast phenomena, such as nuclear reactions.
Molecular or solid-state processes in nature can sometimes take place in time frames as brief as femtoseconds (quadrillionths of a second) or attoseconds (quintillionths of a second). Nuclear reactions are even faster. Now, Maxim Tsarev, Johannes Thurner, and Peter Baum, scientists from the University of Konstanz, are using a new experimental set-up to achieve signals of attosecond duration, i.e. the billionths of a nanosecond, which opens up new perspectives in the field of ultrafast phenomena.
Not even light waves can achieve such a time resolution because a single oscillation takes much too long for that. Electrons provide a remedy here, as they enable significantly higher time resolution. In their experimental set-up, the Konstanz researchers use pairs of femtosecond light flashes from a laser to generate their extremely short electron pulses in a free-space beam. The results are reported in the journal Nature Physics.
Similar to water waves, light waves can also superimpose to create standing or traveling wave crests and troughs. The physicists chose the incidence angles and frequencies so that the co-propagating electrons, which fly through a vacuum at half the speed of light, overlap with optical wave crests and troughs of exactly the same speed.
What is known as ponderomotive force then pushes the electrons in the direction of the next wave trough. Thus, after a short interaction, a series of electron pulses is generated which are extremely short in time especially in the middle of the pulse train, where the electric fields are very strong.
For a short time, the temporal duration of the electron pulses is only about five attoseconds. In order to understand that process, the researchers measure the electrons velocity distribution that remains after compression. Instead of a very uniform velocity of the output pulses, you see a very broad distribution that results from the strong deceleration or acceleration of some electrons in the course of compression, explains physicist Johannes Thurner. But not only that: The distribution is not smooth. Instead, it consists of thousands of velocity steps, since only a whole number of light particle pairs can interact with electrons at a time.
Quantum mechanically, the scientist says, this is a temporal superposition (interference) of the electrons with themselves, after experiencing the same acceleration at different times. This effect is relevant for quantum mechanical experiments for example, on the interaction of electrons and light.
What is also remarkable: Plane electromagnetic waves like a light beam normally cannot cause permanent velocity changes of electrons in a vacuum, because the total energy and the total momentum of the massive electron and a zero rest mass light particle (photon) cannot be conserved. However, having two photons simultaneously in a wave traveling slower than the speed of light solves this problem (Kapitza-Dirac effect).
For Peter Baum, physics professor and head of the Light and Matter Group at the University of Konstanz, these results are still clearly basic research, but he emphasizes the great potential for future research: If a material is hit by two of our short pulses at a variable time interval, the first pulse can trigger a change and the second pulse can be used for observation similar to the flash of a camera.
In his view, the great advantage is that no material is involved in the experimental principle and everything happens in free space. Lasers of any power could in principle be used in the future for ever stronger compression. Our new two-photon compression allows us to move into new dimensions of time and perhaps even film nuclear reactions, Baum says.
Reference: Nonlinear-optical quantum control of free-electron matter waves by Maxim Tsarev, Johannes W. Thurner and Peter Baum, 12 June 2023, Nature Physics.DOI: 10.1038/s41567-023-02092-6
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Groundbreaking Quantum Leap: Physicists Turn Schrdinger’s Cat on Its Head – SciTechDaily
Researchers have developed a groundbreaking method to perform the fractional Fourier Transform of optical pulses using quantum memory. This unique achievement involved implementing the transformation on a Schrdingers cat state, having potential applications in telecommunications and spectroscopy.
Researchers from the University of Warsaws Faculty of Physics, in collaboration with experts from the QOT Centre for Quantum Optical Technologies, have pioneered an innovative technique that allows the fractional Fourier Transform of optical pulses to be performed using quantum memory.
This achievement is unique on the global scale, as the team was the first to present an experimental implementation of the said transformation in this type of system. The results of the research were published in the prestigious journal Physical Review Letters. In their work, the students tested the implementation of the fractional Fourier Transform using a double optical pulse, also known as a Schrdingers cat state.
Waves, such as light, have their own characteristic properties pulse duration and frequency (corresponding, in the case of light, to its color). It turns out that these characteristics are related to each other through an operation called the Fourier Transform, which makes it possible to switch from describing a wave in time to describing its spectrum in frequencies.
The fractional Fourier Transform is a generalization of the Fourier Transform that allows a partial transition from a description of a wave in time to a description in frequency. Intuitively, it can be understood as a rotation of a distribution (for example, the chronocyclic Wigner function) of the considered signal by a certain angle in the time-frequency domain.
Students in the laboratory presenting rotation of Schrdinger cat states. No actual cats were hurt during the project. Credit: S. Kurzyna and B. Niewelt, University of Warsaw
It turns out that transforms of this type are exceptionally useful in the design of special spectral-temporal filters to eliminate noise and enable the creation of algorithms that make it possible to use the quantum nature of light to distinguish pulses of different frequencies more precisely than traditional methods. This is especially important in spectroscopy, which helps study the chemical properties of matter, and telecommunications, which requires the transmission and processing of information with high precision and speed.
An ordinary glass lens is capable of focusing a monochromatic beam of light falling on it to almost a single point (focus). Changing the angle of incidence of light on the lens results in a change in the position of the focus. This allows us to convert angles of incidence into positions, obtaining the analogy of the Fourier Transform, in the space of directions and positions. A classical spectrometer based on a diffraction grating uses this effect to convert the wavelength information of light into positions, allowing us to distinguish between spectral lines.
Similarly to the glass lens, time and frequency lenses allow the conversion of a pulses duration into its spectral distribution, or effectively, perform a Fourier transform in time and frequency space. The right selection of powers of such lenses makes it possible to perform a fractional Fourier Transform. In the case of optical pulses, the action of time and frequency lenses corresponds to applying quadratic phases to the signal.
To process the signal, the researchers used a quantum memory or more precisely a memory equipped with quantum light processing capabilities based on a cloud of rubidium atoms placed in a magneto-optical trap. The atoms were cooled to a temperature of tenths of millions of degrees above absolute zero. The memory was placed in a changing magnetic field, allowing components of different frequencies to be stored in different parts of the cloud. The pulse was subjected to a time lens during writing and reading, and a frequency lens acted on it during storage.
The device developed at the UW allows the implementation of such lenses over a very wide range of parameters and in a programmable way. A double pulse is very prone to decoherence, hence it is often compared to the famous Schrdinger cat a macroscopic superposition of being dead and alive, almost impossible to achieve experimentally. Still, the team was able to implement faithful operations on those fragile dual-pulse states.
The publication was the result of work in the Quantum Optical Devices Laboratory and Quantum Memory Laboratory in the Quantum Optical Technologies center with the participation of two masters students: Stanislaw Kurzyna and Marcin Jastrzebski, two undergraduate students Bartosz Niewelt and Jan Nowosielski, Dr. Mateusz Mazelanik, and lab heads Dr. Michal Parniak and Prof. Wojciech Wasilewski. For the described results, Bartosz Niewelt was also awarded a presentation grant award during the recent DAMOP conference in Spokane, WA.
Before direct application in telecommunications, the method must first be mapped to other wavelengths and parameter ranges. Fractional Fourier transform, however, could prove crucial for optical receivers in state-of-the-art networks, including optical satellite links. A quantum light processor developed at the UW makes it possible to find and test such new protocols in an efficient way.
References: Experimental Implementation of the Optical Fractional Fourier Transform in the Time-Frequency Domain by Bartosz Niewelt, Marcin Jastrzbski, Stanisaw Kurzyna, Jan Nowosielski, Wojciech Wasilewski, Mateusz Mazelanik and Micha Parniak, 12 June 2023, Physical Review Letters.DOI: 10.1103/PhysRevLett.130.240801
The Quantum Optical Technologies (MAB/2018/4) project is carried out within the International Research Agendas program of the Foundation for Polish Science co-financed by the European Union under the European Regional Development Fund.
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Groundbreaking Quantum Leap: Physicists Turn Schrdinger's Cat on Its Head - SciTechDaily
A physics-based Ising solver based on standard CMOS technology – Phys.org
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Quantum computers, systems that perform computations by exploiting quantum mechanics phenomena, could help to efficiently tackle several complex tasks, including so-called combinatorial optimization problems. These are problems that entail identifying the optimal combination of variables among several options and under a series of constraints.
Quantum computers that can tackle these problems should be based on reliable hardware systems, which have an intricate all-to-all node connectivity. This connectivity ultimately allows graphs representing arbitrary dimensions of a problem to be directly mapped onto the computer hardware.
Researchers at University of Minnesota recently developed a new electronic device based on standard complementary metal oxide semiconductor (CMOS) technology that could support this crucial mapping process. This device, introduced in a paper in Nature Electronics, is a physics-based Ising solver comprised of coupled ring oscillators and an all-to-all node connected architecture.
"Building an all-to-all connected hardware where each node (i.e., oscillator) can 'talk' to all other nodes is extremely challenging; as the number of coupled nodes (N) increases, the number of connections per node increases by ~N2. This results in a quadratically increasing electrical loading and hardware overhead for each node which makes the coupling less efficient and less uniform," Chris Kim, one of the researchers who carried out the study, told Phys.org.
"Previous works, including our own, focused on locally connected architecture where each node could talk to only a handful (e.g., <10) of nearby nodes. An all-to-all architecture is ideal as problems can be directly mapped to the hardware but up until this point, there was no elegant way to achieve this."
The Ising solver created by Kim and his colleagues has an all-to-all architecture containing 48 spins and a highly uniform coupling circuit. Horizontal oscillator in the device are closely coupled to vertical oscillators, creating pairs of horizontal-vertical oscillators that intersect with other pairs to form a crossbar array.
"The basic idea behind our Ising solver is to propagate an oscillating signal in both horizontal and vertical directions in a way that node i and node j intersect each other throughout a crossbar array," Kim explained. "By placing a coupler circuit at each intersection, we can build a circuit array where each node signal talks to all other node signals. Despite the oscillating signals being phase shifted throughout the array, coupling between two nodes occurs in a way that accounts for the shifted phases which is why the proposed design finds a competitive solution. "
The researchers evaluated their Ising solver in a series of tests, where they used it to perform various statistical operations, gathering measurements for problems of varying sizes and with different graph densities. Their results were promising, as graphs representing the dimensions of these problems could be effectively mapped onto their chip.
"With our new approach, we can directly map a problem graph with up to 48 nodes to the solver hardware," Kim said. "This is a significant improvement over previous designs; for instance, a King's graph-based hardware was demonstrated by several groups including ours, but each node could only talk to eight other neighbors."
In the future, the chip introduced by Kim and his colleagues could inform the creation of further Ising solvers and devices that can map intricate problem graphs. This could ultimately help to further improve the ability of quantum computers to solve combinatorial optimization problems, facilitating their real-world deployment.
"Since the problems we want to solve are much larger than a single hardware instance, we will have to find a way to decompose and recompose sub-problems without sacrificing the solution accuracy," Kim added.
"Another topic of interest is comparing the solution quality of our hardware against existing optimization algorithms such as simulated annealing or tabu search. Finally, we will have to find more systematic ways to formulate a problem to coupling weights; we cannot democratize this computing approach if a human expert is required at every step of the computation."
More information: Hao Lo et al, An Ising solver chip based on coupled ring oscillators with a 48-node all-to-all connected array architecture, Nature Electronics (2023). DOI: 10.1038/s41928-023-01021-y
Journal information: Nature Electronics
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A physics-based Ising solver based on standard CMOS technology - Phys.org
Researchers make a significant step towards reliably processing quantum information – Phys.org
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Using laser light, researchers have developed the most robust method currently known to control individual qubits made of the chemical element barium. The ability to reliably control a qubit is an important achievement for realizing future functional quantum computers.
The paper, "A guided light system for agile individual addressing of Ba+ qubits with 104 level intensity crosstalk," was published in Quantum Science and Technology.
This new method, developed at the University of Waterloo's Institute for Quantum Computing (IQC), uses a small glass waveguide to separate laser beams and focus them four microns apart, about four-hundredths of the width of a single human hair. The precision and extent to which each focused laser beam on its target qubit can be controlled in parallel is unmatched by previous research.
"Our design limits the amount of crosstalkthe amount of light falling on neighboring ionsto the very small relative intensity of 0.01%, which is among the best in the quantum community," said Dr. K. Rajibul Islam, a professor at IQC and Waterloo's Department of Physics and Astronomy. "Unlike previous methods to create agile controls over individual ions, the fiber-based modulators do not affect each other.
"This means we can talk to any ion without affecting its neighbors while also retaining the capability to control each individual ion to the maximum possible extent. This is the most flexible ion qubit control system with this high precision that we know of anywhere, in both academia and industry."
The researchers targeted barium ions, which are becoming increasingly popular in the field of trapped ion quantum computation. Barium ions have convenient energy states that can be used as the zero and one levels of a qubit and be manipulated with visible green light, unlike the higher energy ultraviolet light needed for other atom types for the same manipulation. This allows the researchers to use commercially available optical technologies that are not available for ultraviolet wavelengths.
The researchers created a waveguide chip that divides a single laser beam into 16 different channels of light. Each channel is then directed into individual optical fiber-based modulators which independently provide agile control over each laser beam's intensity, frequency, and phase. The laser beams are then focused down to their small spacing using a series of optical lenses similar to a telescope. The researchers confirmed each laser beam's focus and control by measuring them with precise camera sensors.
"This work is part of our effort at the University of Waterloo to build barium ion quantum processors using atomic systems," said Dr. Crystal Senko, Islam's co-principal investigator and a faculty member at IQC and Waterloo's Department of Physics and Astronomy. "We use ions because they are identical, nature-made qubits, so we don't need to fabricate them. Our task is to find ways to control them."
The new waveguide method demonstrates a simple and precise method of control, showing promise for manipulating ions to encode and process quantum data and for implementation in quantum simulation and computing.
More information: Ali Binai-Motlagh et al, A guided light system for agile individual addressing of Ba+ qubits with 104 level intensity crosstalk, Quantum Science and Technology (2023). DOI: 10.1088/2058-9565/ace6cb
Journal information: Quantum Science and Technology
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Researchers make a significant step towards reliably processing quantum information - Phys.org
Down the Quantum Rabbit Hole: Alice Ring Discovery Offers Glimpse Into Other-Worldly Realm – SciTechDaily
Artistic illustration of an Alice ring, which researchers have just observed for the first time in nature. Credit: Heikka Valja/Aalto University
Experiments promote a curious flipside of decaying monopoles: a reality where particle physics is quite literally turned on its head.
The field of quantum physics is rife with paths leading to tantalizing new areas of study, but one rabbit hole offers a unique vantage point into a world where particles behave differentlythrough the proverbial looking glass.
Dubbed the Alice ring after Lewis Carrolls world-renowned stories on Alices Adventures in Wonderland, the appearance of this object verifies a decades-old theory on how monopoles decay. Specifically, that they decay into a ring-like vortex, where any other monopoles passing through its center are flipped into their opposite magnetic charges.
Published recently in the journal Nature Communications, these findings mark the latest discovery in a string of work that has spanned the collaborative careers of Aalto University Professor Mikko Mttnen and Amherst College Professor David Hall.
This was the first time our collaboration was able to create Alice rings in nature, which was a monumental achievement, Mttnen said.
This fundamental research opens new doors into understanding how these structures and their analogs in particle physics function in the universe, Hall added.
The long-standing relationship, titled the Monopole Collaboration, initially proved the existence of a quantum analog of the magnetic monopole in 2014, isolated quantum monopoles in 2015, and eventually observed one decay into the other in 2017.
Monopoles remain an elusive concept in the arena of quantum physics. As the name suggests, monopoles are the solitary counterpart of dipoles, which carry a positive charge at their north pole and a negative charge at the south. In contrast, a monopole carries only either a positive or negative charge.
While the concept sounds simple, realizing a true monopole has proven to be a career-defining task. Heres how the Monopole Collaboration has done it: they manipulated a gas of rubidium atoms prepared in a nonmagnetic state near absolute zero temperature. Under these extreme conditions, they were then able to create a monopole by steering a zero point of a three-dimensional magnetic field into the quantum gas.
These quantum monopoles are ephemeral by nature, decaying a few milliseconds after their creation. It is within this instability that the Alice ring takes shape.
Think of the monopole as an egg teetering at the top of a hill, Mttnen said. The slightest perturbations can send it crashing down. In the same way, monopoles are subject to noise that triggers their decay into Alice rings.
While monopoles are short-lived, the research group simulated stable Alice rings for as long as 84 millisecondsover 20 times longer than the monopole lifespan. This leads researchers to be optimistic that future experiments will reveal even more peculiar properties of Alice rings.
From a distance, the Alice ring just looks like a monopole, but the world takes a different shape when peering through the center of the ring, Hall said.
It is from this perspective that everything seems to be mirrored, as if the ring were a gateway into a world of antimatter instead of matter, Mttnen added.
In theory, a monopole passing through the center of an Alice ring would be transformed into an anti-monopole of opposite charge. Correspondingly, the Alice rings charge would change as well. While this phenomenon has not yet been experimentally observed, Mttnen said the topological structure of Alice rings necessitates this behavior.
The experimental work was conducted at Amherst College primarily by PhD candidate Alina Blinova and Hall, while Mttnen and his team were responsible for running matching simulations. This way, the two teams were able to confirm the interpretation of the experimental observations.
It is simply amazing to have such a major discovery as the finale of my PhD work, Blinova said.
Reference: Observation of an Alice ring in a BoseEinstein condensate by Alina Blinova, Roberto Zamora-Zamora, Tuomas Ollikainen, Markus Kivioja, Mikko Mttnen and David S. Hall, 29 August 2023, Nature Communications.DOI: 10.1038/s41467-023-40710-2
The simulations conducted at Aalto University were made possible by support from the CSC IT Center for Science and the Research Council of Finland through its Centre of Excellence in Quantum Technology, and the experiments in the US by the financial support of the National Science Foundation.
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Kuano raises closes 1.8M harnessing quantum mechanics and AI … – Tech.eu
Today drug discovery company Kuano, announced the close of a 1.8 million seed funding round.
The company combines quantum mechanics with AI to design the next generation of medicines, focusing on seeing and modelling enzymes.
Dysfunctional enzymes are implicated in many human diseases.
However, until now, scientists have only been able to view enzymes in their resting state, not fully functioning dynamic states.
As different enzymes may appear very similar in a resting state, drugs designed to target one may also affect others, potentially impacting drug safety and efficacy.
Kuanos quantum simulation platform enables scientists to see and model enzymes in their dynamic state, opening new possibilities for more effective drug design.
Combining these unique enzyme profiles with its suite of AI tools, Kuano predicts the best structures with which to target them. Drug candidates designed this way are more likely to be more potent with fewer side effects. The platform is validated in three separate disease areas, including bowel cancer and lymphoma.
Kuano was co-founded in 2020 by Drs. Vid Stojevic, an expert in quantum physics and AI; David Wright, who specialises in molecular modelling and simulation, Parminder Ruprah, a highly experienced drug hunter; and Jarryl DOyley, an expert computational medicinal chemist.
Vid Stojevic, Co-founder and CEO, Kuano, said:
Our platform creates a quantum lens that reveals the difference between enzymes and allows us to target each one individually without affecting the others.
This funding round will not only allow us to continue our laboratory work, but also to strengthen our management team and prepare the Company for scaling.
Mercia Ventures led the round, which included ACF Investors, Ascension Ventures, o2h Ventures, Meltwind Advisory LLP, and other Angel investors.Robert Hornby from Mercia, shared:
Fewer than 20% of enzymes have so far been targeted by drugs because of the difficulty in understanding their dynamic states.
Kuanos quantum simulation platform goes beyond existing AI models and means they can design drugs for previously undruggable enzymes.
The Company addresses a huge untapped market and has already attracted the attention of leading pharmaceutical companies. This investment will enable it to move to the next stage.
The investment will facilitate further validation of Kuanos quantum simulation platform for the design of more effective drug candidates targeting enzymes and continued company growth through strategic partnerships and recruitment.
Lead image: Martin Lopez
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Kuano raises closes 1.8M harnessing quantum mechanics and AI ... - Tech.eu
Experimental physicist David Weld to investigate the role of … – The UCSB Current
Whats really unexplored experimentally is what happens if you take the results of those measurements and feed them back to future parameters of the system, said Weld, who will be collaborating with UCSB physicist Andrew Jayich for this project. One way feedback could be useful is in the realm of quantum error correction, in which the feedback protects information in qubits for more robust quantum computing. But thats just one example of a broader space of possibilities where you could have new behaviors, new phenomena and new states of matter emerging as you add these feedback elements, he said.
To set the stage for potential new behaviors and phenomena, the research team is developing an experimental apparatus that combines atoms at ultracold temperatures where quantum behaviors become important and optical tweezers, which are focused lasers that allow the researchers to trap and manipulate these atoms. Using arrays of tweezers to manipulate large ensembles of ultracold atoms in this tightly controlled environment, the researchers would be able to explore the physics of many-body quantum systems, in which many particles interact with each other and their structured classical environment to potentially produce emergent behaviors. Using thousands of atoms may also allow the researchers to perform weak measurements, gaining insight into the dynamics of the system without the usual complete loss of quantum properties that come with measurement.
It opens up this possibility that were excited about to do partial measurement and feedback, without destroying the quantum state, Weld said.
According to the Moore Foundation, Dr. Welds work to develop techniques for controlling the flow of entropy, energy and information in quantum systems could have a major impact on all scientific or technological platforms which rely on quantum control.
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Experimental physicist David Weld to investigate the role of ... - The UCSB Current