Spiraling laser light reveals how topological insulators lose their ability to conduct electric current on their surfaces.

In 2019, Google showed that its Sycamore quantum computer could solve a problem that no ordinary computer could handle - but now a new algorithm gives non-quantum devices the edge

Researchers report an experimental demonstration of a space-to-ground quantum key distribution (QKD) network using a compact QKD terminal aboard the Chinese Space Lab Tiangong-2 and four ground stations. The new QKD system is less than half the weight of the system the researchers developed for the Micius satellite, which was used to perform the world's first quantum-encrypted virtual teleconference.

Quantum computers promise to dramatically affect selected application fields, including materials synthesis, pharmaceutical drug development, and cybersecurity—to name a few.

Topological insulators, or TIs, have two faces: Electrons flow freely along their surface edges, like cars on a superhighway, but can't flow through the interior of the material at all. It takes a special set of conditions to create this unique quantum state—part electrical conductor, part insulator—which researchers hope to someday exploit for things like spintronics, quantum computing and quantum sensing. For now, they're just trying to understand what makes TIs tick.

Author(s): Michael SchirberThe spin state of molecular qubits can be made more stable by changing the chemical environment in which the qubits sit. [Physics 15, s116] Published Thu Aug 18, 2022

Faster computers, tap-proof communication, better car sensors—quantum technologies have the potential to revolutionize our lives just as the invention of computers or the internet once did. Experts worldwide are trying to implement findings from basic research into quantum technologies. To this end, they often require individual particles, such as photons—the elementary particles of light—with tailored properties.

Trapped ion computers are quantum computers in which the qubits (quantum units of information) are ions trapped by electric fields and manipulated with lasers. To avoid crosstalk between nearby qubits, physicists and engineers design these computers using two different types of qubits.

Multiverse Computing, a developer of quantum computing solutions, and IKERLAN, a Spain-based center supporting the transfer of technology, developed a quantum-enhanced kernel method for classification on universal gate-based quantum computers, as well as a quantum classification algorithm on a quantum annealer. Results of the joint research study showed detected defects in manufactured car pieces via image classification by quantum artificial vision systems. The researchers found that both algorithms used in the kernel classification method outperformed common classical methods in the identification of relevant images and the accurate classification of manufacturing defects. Ion Etxeberria, CEO of IKERLAN, said that the study...

Recent research proves that under certain conditions, quantum annealing computers can run algorithms—including the well-known Shor's algorithm—more quickly than classical computers. In most cases, however, quantum annealing does not provide a speed-up compared to classical computing when time is limited, according to a study in Nature Communications.

One of the long-promised benefits of quantum computers is simulating molecules very quickly, but it turns out that these extra-fast speeds might not be possible

Quantum computing technology could have notable advantages over classical computing technology, including a faster speed and the ability to tackle more complex problems. In recent years, some researchers have also been exploring the possible establishment of a "quantum internet," a network that would allow quantum devices to exchange information, just like classical computing devices exchange information today.

By using photons and electron spin qubits to control nuclear spins in a two-dimensional material, researchers have opened a new frontier in quantum science and technology, enabling applications like atomic-scale nuclear magnetic resonance spectroscopy, and to read and write quantum information with nuclear spins in 2D materials.

An international research team has detected novel quantum effects in high-precision studies of natural double-layer graphene and has interpreted them using their theoretical work.

An international research team led by the University of Göttingen has detected novel quantum effects in high-precision studies of natural double-layer graphene and has interpreted them together with the University of Texas at Dallas using their theoretical work. This research provides new insights into the interaction of the charge carriers and the different phases, and contributes to the understanding of the processes involved. The LMU in Munich and the National Institute for Materials Science in Tsukuba, Japan, were also involved in the research. The results were published in Nature.

By using photons and electron spin qubits to control nuclear spins in a two-dimensional material, researchers at Purdue University have opened a new frontier in quantum science and technology, enabling applications like atomic-scale nuclear magnetic resonance spectroscopy, and to read and write quantum information with nuclear spins in 2D materials.

Topology and entanglement are two powerful principles for characterizing the structure of complex quantum states. In a new

Simulations of a quantum computer made of six rubidium atoms suggest it could run a simple brain-inspired algorithm that can learn to remember and make simple decisions

In Einstein's theory of general relativity, gravity arises when a massive object distorts the fabric of spacetime the way a ball sinks into a piece of stretched cloth. Solving Einstein's equations by using quantities that apply across all space and time coordinates could enable physicists to eventually find their "white whale": a quantum theory of gravity.

When Google announced its quantum computer had solved a problem beyond the capability of the most powerful supercomputer, it was a landmark for the industry. But Chinese researchers have now shown they can solve the same problem on a normal supercomputer in just seconds. The ultimate promise of quantum computing is its ability to carry […]

The first pulsar was discovered in 1967. With an increase in pulsar observations, astronomers have found that some pulsars have a proper motion velocity greater than 1000 km/s, and the number of such pulsars is growing each year.

A team of physicists have created and observed an entirely new class of vortices – tiny and exotic

A team based at Princeton University has accurately simulated the initial steps of ice formation by applying artificial

Topology and entanglement are two powerful principles for characterizing the structure of complex quantum states. In a new paper in the journal Physical Review X, researchers from the University of Pennsylvania establish a relationship between the two.

From water boiling into steam to ice cubes melting in a glass, we've all seen the phenomenon known as a phase transition in our everyday lives. But there's another type of phase transition that's much harder to see, but just as stark: quantum phase transitions.

Scientists at the National Institute of Standards and Technology (NIST) and JILA, formerly the Joint Institute for Laboratory Astrophysics, developed a miniaturized optical tweezer that captured single atoms. The challenging task of single-atom captures has implications in quantum technologies, for which single atoms can provide a platform. A means to trap and manipulate single atoms is required for the operation of quantum devices such as atomic clocks and quantum computers. If individual atoms can be collected and controlled in large arrays, they can serve as qubits, which could enable quantum computers to perform calculations at far greater speeds than today’s fastest supercomputer. The researchers used the nanosize...

Quantum field theory may be the most successful scientific theory of all time, but there’s reason to think it’s missing something. Steven Strogatz speaks with theoretical physicist David Tong about this enigmatic theory. The post What Is Quantum Field Theory and Why Is It Incomplete? first appeared on Quanta Magazine

An international collaboration of scientists has created and observed an entirely new class of vortices—the whirling masses of fluid or air.

Demonstration involving Rydberg atoms paves the way to scalable quantum computers, researchers say.

In large systems of interacting particles in quantum mechanics, an intriguing phenomenon often emerges: groups of particles begin to behave like single particles. Physicists refer to such groups of...

Author(s): Rachel BerkowitzA three-qubit transistor design offers a way to manipulate the system’s heat flow by hitting one of the qubits with a laser.   [Physics 15, s103] Published Tue Aug 09, 2022

Researchers at Massachusetts Institute of Technology (MIT), the MIT-Harvard Center for Ultracold Atoms, Harvard University and Stanford University have recently unveiled the existence of unique helical spin states in Heisenberg quantum magnets. Their observations, published in a paper in Nature Physics, could have important implications for the simulation of spin-related physical processes and dynamics in quantum many-body systems.

A research team in Japan’s Institute for Molecular Science (IMS), National Institutes of Natural Sciences (NINS) has executed a two-qubit gate — a fundamental operation for quantum computing — that operates in just 6.5 ns. The team believes that its advancement is poised to support a next wave of success in ultrafast quantum computing. Ultrafast quantum computing that relies on lasers to manipulate cold atoms trapped with optical tweezers is expected to support a quantum computer architecture that breaks through the limitations of the superconducting and trapped-ion types currently in development, the researchers said. Cold-atom quantum computers are based on laser cooling and trapping techniques, which...

A fabrication technique developed by researchers at the University of Oxford enabled the rapid production of waveguides in a chip with precisely controlled 3D cross sections that exhibited changing behavior along the waveguide. The waveguides were demonstrated with very low losses and show promise for the design of photonic and/or quantum chips. Among the basic components of PICs are micron-scale optical waveguides. The elements are analogous to the semiconductor diodes of conventional electronic integrated circuits. Due to limitations in fabrication, the optical waveguides are limited to two-dimensional square, elliptic, and circular cross-section architectures. Current options are limited in the production of these waveguides to...

A research group led by graduate student Yeelai Chew, Assistant Professor Sylvain de Léséleuc and Professor Kenji Ohmori at the Institute for Molecular Science, National Institutes of Natural Sciences, is using atoms cooled to almost absolute zero and trapped in optical tweezers separated by a micron or so (see Fig. 1). By manipulating the atoms with a special laser light for 10 picoseconds, they succeeded in executing the world's fastest two-qubit gate, a fundamental operation essential for quantum computing, which operates in just 6.5 nanoseconds.

A team of researchers at Google's Quantinuum, working with a colleague at the University of Texas, Austin, has developed a way to simulate infinitely many chaotic particles using a quantum computer running with a limited number of qubits. In their paper published in the journal Nature Physics, the group describes their technique.

Quantum clocks are normally controlled by a classical control system, but to build things like tiny quantum drones that fly around delivering molecules we'll need a fully quantum approach

A player using a quantum algorithm will win the codebreaking game Mastermind, which has the same underlying principles as Wordle, more often and in fewer moves than someone using a classical algorithm

The LHCb experiment at CERN recently announced the first proton-proton collisions at a world-record energy with its brand-new detector designed to cope with much more demanding data-taking conditions.

Using just a handful of quantum bits, researchers have used a quantum computer to simulate an infinite line of electron-like particles. The technique could be used to better understand the behaviour of molecules in materials

A research partnership at the Advanced Quantum Testbed (AQT) at Lawrence Berkeley National Laboratory (Berkeley Lab) and Chicago-based Super.tech (acquired by ColdQuanta in May 2022) demonstrated how to optimize the execution of the ZZ SWAP network protocol, important to quantum computing. The team also introduced a new technique for quantum error mitigation that will improve the network protocol's implementation in quantum processors. The experimental data was published this July in Physical Review Research, adding more pathways in the near term to implement quantum algorithms using gate-based quantum computing.

Tiny crystals, known as quantum dots, have enabled an international team to achieve a quantum efficiency exceeding 100 percent in the photocurrent generated in a hybrid inorganic-organic semiconductor.

Physicists are (temporarily) augmenting reality to crack the code of quantum systems.

Author(s): Sara BolognesiLong-baseline neutrino experiments are paving the way for the solution of two outstanding puzzles in neutrino physics—mass ordering and charge-parity violation. [Physics 15, 120] Published Wed Aug 03, 2022

Physicists have been trying to determine the ground states of 2D electron systems at extremely low densities and temperatures for many decades now. The first theoretical predictions for these ground states were put forward by physicists Felix Bloch in 1929 and Eugene Wigner in 1934, both of whom suggested that interactions between electrons could lead to ground states that had never been observed before.

The leading UK-based nanomaterials innovator Quantum Science has launched INFIQ® lead-free (LF) – quantum dot (QD), a quantum dot technology that is lead-free, and continues to push the...

Superfast algorithm put crimp in 2019 claim that Google’s machine had achieved “quantum supremacy”

Quantum computing, though still in its early days, has the potential to dramatically increase processing power by harnessing the strange behavior of particles at the smallest scales. Some research groups have already reported performing calculations that would take a traditional supercomputer thousands of years. In the long term, quantum computers could provide unbreakable encryption and simulations of nature beyond today's capabilities.

One of the cornerstones of the implementation of quantum technology is the creation and manipulation of the shape of external fields that can optimize the performance of quantum devices. Known as quantum optimal control, this set of methods comprises a field that has rapidly evolved and expanded over recent years.

City College of New York physicist Pouyan Ghaemi and his research team are claiming significant progress in using quantum

Speed limits for quantum phenomena have been extended to macro-sized objects.

A roadmap for the future direction of quantum simulation.

The LEGEND-200 detector could help explain why matter dominates the known universe

A roadmap for the future direction of quantum simulation has been set out in a paper co-authored at the University of Strathclyde.

Yet-to-be discovered axions and axion-like particles may be the key to explaining some of the deepest puzzles of our universe, such as dark matter and charge-parity violation in strong interactions. Several recent theories have predicted that the masses of axions probably lie within the well-motivated "axion window" (0.01 meV–1 meV). However, existing laboratory searches and astrophysical observation mostly search for the axions outside the axion window.

Author(s): Michael SchirberOn the road to a quantum internet, researchers demonstrate entanglement of two memory elements located 12.5 km apart in an urban environment. [Physics 15, s101] Published Thu Jul 28, 2022

Quantum computing, a field that relies on the principles of quantum mechanics to calculate outcomes, has the potential to perform tasks too complex for traditional computers and to do so at high speeds, making it in some ways the new frontier for science and engineering. To get to the point where quantum computers can meet their expected performance potential, the development of large-scale quantum processors and quantum memories is needed. Precise control of qubits—or quantum bits, the basic building blocks of quantum computers—is critical to do this, but methods of controlling qubits have limitations for massive high-density wiring with high precision.

An expression for the maximum speed at which changes in macroscopic systems can occur has been derived by a theoretical physicist at RIKEN. This will deepen our understanding of quantum phenomena in systems that are not in equilibrium.

Scientists at the Department of Energy’s Oak Ridge National Laboratory used neutron scattering to determine whether a specific

Scientists have used neutron scattering to determine whether a specific material's atomic structure could host a novel state of matter called a spiral spin liquid. By tracking tiny magnetic moments known as 'spins' on the honeycomb lattice of a layered iron trichloride magnet, the team found the first 2D system to host a spiral spin liquid.

Scientists at the Oak Ridge National Laboratory used neutron scattering to determine whether a specific material's atomic structure could host a novel state of matter called a spiral spin liquid. By tracking tiny magnetic moments known as "spins" on the honeycomb lattice of a layered iron trichloride magnet, the team found the first 2D system to host a spiral spin liquid.

Physicists are claiming significant progress in using quantum computers to study and predict how the state of a large number of interacting quantum particles evolves over time. This was done by developing a quantum algorithm that they run on an IBM quantum computer.

An international team has successfully implemented an advanced form of quantum cryptography for the first time. Moreover, encryption is independent of the quantum device used and therefore even more secure against hacking attempts.

A method known as quantum key distribution has long held the promise of communication security unattainable in conventional cryptography. An international team of scientists has now demonstrated experimentally, for the first time, an approach to quantum key distribution that is based on high-quality quantum entanglement -- offering much broader security guarantees than previous schemes.

Author(s): Sophia ChenThree experiments demonstrate the key elements of a quantum cryptographic scheme that predictions indicate should be unhackable, bringing the promise of quantum encryption technologies a step closer to reality. [Physics 15, 116] Published Wed Jul 27, 2022

The way we currently send secure information over the internet – like credit card details – is under threat from quantum computing. Our current methods of encrypting data are very difficult to crack with current computers, but the next generation of quantum computers would be able to do it. But two new studies suggest that, […]

Bell tests proved that quantum mechanics really is “spooky.” Now they’ve made quantum communication even more hacker-proof.

A method known as quantum key distribution has long held the promise of communication security unattainable in conventional cryptography. An international team of scientists has now demonstrated experimentally, for the first time, an approach to quantum key distribution that is based on high-quality quantum entanglement—offering much broader security guarantees than previous schemes.

The Internet is teeming with highly sensitive information. Sophisticated encryption techniques generally ensure that such content cannot be intercepted and read. But in the future high-performance quantum computers could crack these keys in a matter of seconds. It is just as well, then, that quantum mechanical techniques not only enable new, much faster algorithms, but also exceedingly effective cryptography.

City College of New York physicist Pouyan Ghaemi and his research team are claiming significant progress in using quantum computers to study and predict how the state of a large number of interacting quantum particles evolves over time. This was done by developing a quantum algorithm that they run on an IBM quantum computer. "To the best of our knowledge, such particular quantum algorithm which can simulate how interacting quantum particles evolve over time has not been implemented before," said Ghaemi, associate professor in CCNY's Division of Science.

Quantum computers, devices that exploit quantum phenomena to perform computations, could eventually help tackle complex computational problems faster and more efficiently than classical computers. These devices are commonly based on basic units of information known as quantum bits, or qubits.

The origins of high-energy particles that bombard the Earth from deep space may have been revealed for the first time by new research.

Research drawing on the quantum 'anti-butterfly effect' solves a longstanding experimental problem in physics and establishes a method for benchmarking the performance of quantum computers.

Research drawing on the quantum "anti-butterfly effect" solves a longstanding experimental problem in physics and establishes a method for benchmarking the performance of quantum computers.

Single-shot spectroscopy techniques provide researchers with a new understanding of a mysterious light-driven process. The development of high-speed

When studying a complex system, scientists identify smaller pieces called subsystems that they can make sense of. By studying subsystems and the correlations between them, they reconstruct an understanding of the whole.

 Thomas Iadecola worked through the title of the latest research paper that includes his theoretical and analytical work,

The development of high-speed strobe-flash photography in the 1960s by the late MIT professor Harold "Doc" Edgerton allowed us to visualize events too fast for the eye—a bullet piercing an apple, or a droplet hitting a pool of milk.

For decades computers have been synonymous with binary information -- zeros and ones. Now a team has realized a quantum computer that breaks out of this paradigm and unlocks additional computational resources, hidden in almost all of today's quantum devices.

Researchers have created a "quantum flute" that coaxes light particles to interact in a way that's never been seen before.

Via large-scale simulations on supercomputers, a research team from the Department of Physics, the University of Hong Kong (HKU), discovered clear evidence to characterize a highly entangled quantum matter phase—the quantum spin liquid (QSL), a phase of matter that remains disordered even at very low temperatures. This research has recently been published in npj Quantum Materials.

We all learn from early on that computers work with zeros and ones, also known as binary information. This approach has been so successful that computers now power everything from coffee machines to self-driving cars and it is hard to imagine a life without them.

Quantum computers hold the promise of revolutionising information technology by utilising the whacky physics of quantum mechanics. But playing with strange, new machinery often throws up even more interesting and novel physics. This is precisely what has happened to quantum computing researchers in the US. Reported in Nature, physicists who were shining a pulsing laser […]

Two players leverage quantum rules to achieve a seemingly telepathic connection

Physicists have demonstrated how simulations using quantum computing can enable observation of a distinctive state of matter taken out of its normal equilibrium. Such novel states of matter could one day lead to developments in fast, powerful quantum information storage and precision measurement science.

Thomas Iadecola worked his way through the title of the latest research paper that includes his theoretical and analytical work, patiently explaining digital quantum simulation, Floquet systems and symmetry-protected topological phases.