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Category: quantum physics – Page 248

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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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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Spintronics is a field that deals with electronics that exploit the intrinsic spin of electrons and their associated magnetic moment for applications such as quantum computing and memory storage devices. Owing to its spin and magnetism exhibited in its insulator-metal phase transition, the strongly correlated electron systems of nickel oxide (NiO) have been thoroughly explored for more than eight decades. Interest in its unique antiferromagnetic (AF) and spin properties has seen a revival lately since NiO is a potential material for ultrafast spintronics devices.

Despite this rise in popularity, exploration of its magnetic properties using the low-energy electron diffraction (LEED) technique has not received much attention since the 1970s. To review the understanding of the surface properties, Professor Masamitsu Hoshino and Emeritus Professor Hiroshi Tanaka, both from the Department of Physics at Sophia University, Japan, revisited the surface LEED crystallography of NiO.

The results of their quantitative experimental study investigating the coherent exchange scattering in Ni2+ ions in AF single crystal NiO were reported in The European Physical Journal D.

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Quantum traffic laws applied to the 3D streetscape of a specific kind of crystal can put the brakes on electron rush hour.

In a search for novel materials that can contain bizarre new states of matter, physicists from Rice University in the US led an experiment that forced free-roaming electrons to stay in place.

While the phenomenon has been seen in materials where electrons are constrained to just two dimensions, this is the first time it’s been observed in a three-dimensional crystal metal lattice, known as a pyrochlore. The technique gives researchers a new tool for studying the less conventional activities of plucky, charge-carrying particles.

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Condensed matter systems and photonic technologies are regularly used by researchers to create microscale platforms that can simulate the complex dynamics of many interacting quantum particles in a more accessible setting. Some examples include ultracold atomic ensembles in optical lattices, superconducting arrays, and photonic crystals and waveguides. In 2006 a new platform emerged with the demonstration of macroscopically coherent quantum fluids of exciton-polaritons to explore many-body quantum phenomena through optical techniques.

When a piece semiconductor is placed between two mirrors—an optical microresonator—the electronic excitations within can become strongly influenced by photons trapped between the mirrors. The resulting new bosonic , known as exciton-polaritons (or polaritons for short), can under the right circumstances undergo a phase transition into a nonequilibrium Bose-Einstein condensate and form a macroscopic quantum fluid or a droplet of light.

Quantum fluids of polaritons have many salient properties, one being that they are optically configurable and readable, permitting easy measurements of the dynamics. This is what makes them so advantageous to simulate many-body physics.

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Universal behavior is a central property of phase transitions, which can be seen, for example, in magnets that are no longer magnetic above a certain temperature. A team of researchers from Kaiserslautern, Berlin and Hainan, China, has succeeded for the first time in observing such universal behavior in the temporal development of an open quantum system, a single cesium atom in a bath of rubidium atoms.

This finding helps to understand how quantum systems reach equilibrium. This is of interest to the development of quantum technologies, for example. The study has been published in Nature Communications.

Phase transitions in chemistry and physics are changes in the state of a substance, for example, the change from a liquid to a gaseous phase, when an external parameter such as temperature or pressure is changed.

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Generating quantum correlations between light and microwaves.

Non-classical microwave–optical photon pair generation with a chip-scale transducer.

A transducer that generates microwave–optical photon pairs is demonstrated. This could provide an interface between optical communication networks and superconducting quantum devices that operate at microwave frequencies.

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