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Archive for the ‘quantum physics’ category: Page 24

Mar 9, 2024

A New Hall Effect from Quantum Geometry

Posted by in categories: quantum physics, space

Throughout many branches of physics, a connection can be drawn between geometry and dynamics. In general relativity, for example, the motion of stars and planets is governed by the geometry of spacetime. In condensed matter, the motion of electrons in solids is influenced by the so-called quantum geometry, which describes how the electronic wave function evolves in momentum space. The quantum geometry can explain a wide range of observed phenomena, such as topological phases and quantum Hall effects, but it can also lead researchers to new electromagnetic responses. Guided by quantum-geometry predictions, Lujunyu Wang from Peking University and colleagues present experimental evidence of a new Hall effect, the magneto-nonlinear Hall effect, which is proportional to both an in-plane electric field and an in-plane magnetic field [1] (Fig. 1). The effect, which was isolated in a magnet with triangular symmetry, offers a new way to probe in the quantum geometry of materials.

Quantum geometry is a representation of the phase of the Bloch wave functions, which describe electronic behavior in a periodic potential. In the case of a two-level system, this phase can be represented by a unit vector in the momentum space of the electrons. In certain materials, this vector rotates as the momentum changes, an effect that can be characterized by two fundamental geometrical properties: the “quantum metric” and the “Berry curvature.” These two aspects of quantum geometry can describe many phenomena including surface currents in topological insulator and anomalous Hall effects in which the transverse Hall current occurs in the absence of an external magnetic field.

Recently, researchers have uncovered a connection between quantum geometry and nonlinear electromagnetic effects [210]. Here, the nonlinearity is a higher-order response to the input electromagnetic fields. Nonlinear electrical transport is the foundation of applications such as rectification and wave mixing. Classically, the most well-known nonlinear device is a p-n junction. In quantum materials, nonlinear transport suggests novel device applications but also provides a powerful probe of the quantum geometry of the conduction electrons.

Mar 9, 2024

A Quantum Gas Microscope with Depth Perception

Posted by in categories: particle physics, quantum physics

Researchers have developed a quantum gas microscope that can pinpoint the horizontal and vertical positions of atoms arranged in a lattice.

Mar 9, 2024

Quantum Gravity Unveiled — Scientists Crack the Cosmic Code That Baffled Einstein

Posted by in categories: particle physics, quantum physics

Physicists successfully measure gravity in the quantum world, detecting weak gravitational pull on a tiny particle with a new technique that uses levitating magnets, putting scientists closer to solving mysteries of the universe.

Scientists are a step closer to unraveling the mysterious forces of the universe after working out how to measure gravity on a microscopic level.

Experts have never fully understood how the force discovered by Isaac Newton works in the tiny quantum world.

Mar 9, 2024

Breaking Barriers in Quantum Research: Magnesium-Coated Tantalum Unveiled

Posted by in categories: computing, quantum physics

Scientists at the DOE’s Brookhaven National Laboratory have discovered that coating tantalum with magnesium significantly enhances its properties as a superconducting material for quantum computing. This coating prevents oxidation, increases purity, and improves the superconducting transition temperature of tantalum, offering promising advancements for the development of qubits and the future of quantum computing.

Scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have discovered that adding a layer of magnesium improves the properties of tantalum, a superconducting material that shows great promise for building qubits, the basis of quantum computers.

As described in a paper just published in the journal Advanced Materials, a thin layer of magnesium keeps tantalum from oxidizing, improves its purity, and raises the temperature at which it operates as a superconductor. All three may increase tantalum’s ability to hold onto quantum information in qubits.

Mar 9, 2024

Scientists propose new scheme for the quantum battery using waveguides

Posted by in categories: energy, quantum physics

A new study by researchers at Lanzhou University and Hubei University proposes a quantum battery (QB) charging scheme based on a rectangular hollow metal waveguide. This approach allows them to overcome environment-induced decoherence and charging distance limitations. The findings are published in Physical Review Letters.

The demand and supply for batteries continue to grow with a focus on enhancing energy storage, longevity, and charging capabilities. On this front, scientists are now developing quantum batteries that leverage principles of quantum mechanics to store and supply energy.

The aim is to use fundamental principles of quantum mechanics such as entanglement and coherence to overcome the constraints of classical physics, thereby achieving stronger charging power, higher charging capacity, and larger work extraction compared to classical counterparts.

Mar 9, 2024

Multiparticle nanostructures for building better quantum technologies

Posted by in categories: nanotechnology, quantum physics

In Nature Physics, the LSU Quantum Photonics Group offers fresh insights into the fundamental traits of surface plasmons, challenging the existing understanding. Based on experimental and theoretical investigations conducted in Associate Professor Omar Magaña-Loaiza’s laboratory, these novel findings mark a significant advancement in quantum plasmonics, possibly the most noteworthy in the past decade.

While prior research in the field has predominantly focused on the collective behaviors of plasmonic systems, the LSU group adopted a distinct approach. By viewing plasmonic waves as a puzzle, they were able to isolate multiparticle subsystems, or break down the puzzle into pieces. This allowed the team to see how different pieces work together and revealed a different picture, or in this case, new behaviors for .

Plasmons are waves that move along the surface of metals when light is coupled to charge oscillations. Much like tossing pebbles into water generates ripples, plasmons are “ripples” traveling along metal surfaces. These minute waves operate on a nanometer scale, rendering them crucial in fields such as nanotechnology and optics.

Mar 9, 2024

Drug design on quantum computers

Posted by in categories: chemistry, computing, quantum physics

Quantum computers promise to efficiently predict the structure and behaviour of molecules. This Perspective explores how this could overcome existing challenges in computational drug discovery.

Mar 9, 2024

Spacetime from Entanglement Entropy! | with Tadashi Takayanagi

Posted by in category: quantum physics

A holographic universe where spacetime is built from quantum bits. In this interview, we hear all about how the concept of entanglement entropy, a measure of quantum information between regions is related to the structure of spacetime. What can we learn from entanglement and entropy about gravity, and what has gravity to say about quantum physics? We find out in this video.

Tadashi Takayanagi is a prominent Japanese researcher most known for his research on holographic entanglement entropy for which he won the 2015 New Horizon award. Tadashi did his Ph.D. at Tokyo University and has obtained postdoc positions at Harvard and Kavli Institute of Theoretical Physics at the University of California. He is currently a professor at Kyoto University and holds a visiting position at Kavli Institute. A well-known hobby of Tadashi is his mineral collection from which he draws inspiration for his research work.

Mar 9, 2024

Assembly Theory: Bold New ‘Theory of Everything’ Could Unite Physics And Evolution

Posted by in categories: biotech/medical, engineering, evolution, quantum physics

A recent study conducted at Tel Aviv University has devised a large mechanical system that operates under dynamical rules akin to those found in quantum systems. The dynamics of quantum systems, composed of microscopic particles like atoms or electrons, are notoriously difficult, if not impossible, to observe directly.

However, this new system allows researchers to visualize occurring in specialized “topological” materials through the movement of a system of coupled pendula.

The research is a collaboration between Dr. Izhar Neder of the Soreq Nuclear Research Center, Chaviva Sirote-Katz of the Department of Biomedical Engineering, Dr. Meital Geva and Prof. Yair Shokef of the School of Mechanical Engineering, and Prof. Yoav Lahini and Prof. Roni Ilan of the School of Physics and Astronomy at Tel Aviv University and was recently published in the Proceedings of the National Academy of Sciences.

Mar 9, 2024

Novel method improves Fourier transform infrared spectroscopy detection of ultra-low concentration trace substances

Posted by in categories: biotech/medical, engineering, quantum physics

A recent study conducted at Tel Aviv University has devised a large mechanical system that operates under dynamical rules akin to those found in quantum systems. The dynamics of quantum systems, composed of microscopic particles like atoms or electrons, are notoriously difficult, if not impossible, to observe directly.

However, this new system allows researchers to visualize occurring in specialized “topological” materials through the movement of a system of coupled pendula.

The research is a collaboration between Dr. Izhar Neder of the Soreq Nuclear Research Center, Chaviva Sirote-Katz of the Department of Biomedical Engineering, Dr. Meital Geva and Prof. Yair Shokef of the School of Mechanical Engineering, and Prof. Yoav Lahini and Prof. Roni Ilan of the School of Physics and Astronomy at Tel Aviv University and was recently published in the Proceedings of the National Academy of Sciences.

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