Category Physics

A valley so low: Electrons Congregate in ways that could be useful to ‘Valleytronics’

Elliptical orbits of bismuth surface electrons in a large magnetic field. The orientation and interference patterns of the electronic states reveal that the electrons prefer to occupy a single valley. Image created using a theoretical model of the data. Credit: Ali Yazdani Laboratory, Princeton University

Elliptical orbits of bismuth surface electrons in a large magnetic field. The orientation and interference patterns of the electronic states reveal that the electrons prefer to occupy a single valley. Image created using a theoretical model of the data.
Credit: Ali Yazdani Laboratory, Princeton University

Researchers have made a finding that could help usher in new area of technology called ‘valleytronics.’ The study found that electrons in bismuth crystals prefer to collect in one valley rather than being distributed equally across valleys, setting up a type of electricity known as ferroelectricity. Energy valleys forming in crystals can trap single electrons. These valleys potentially could be used to store information, greatly enhancing what is capable with modern electronic devices.

In ...

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Smallest Transistor Switches Current with a Single Atom in Solid Electrolyte

The single-atom transistor that works in a gel electrolyte reaches the limit of miniaturization. Credit: Group of Professor Thomas Schimmel/KIT

The single-atom transistor that works in a gel electrolyte reaches the limit of miniaturization.
Credit: Group of Professor Thomas Schimmel/KIT

Milestone of energy efficiency in information technology. At Karlsruhe Institute of Technology (KIT), physicist Professor Thomas Schimmel and his team have developed a single-atom transistor, the world’s smallest. This quantum electronics component switches electrical current by controlled repositioning of a single atom, now also in the solid state in a gel electrolyte. The single-atom transistor works at room temperature and consumes very little energy, which opens up entirely new perspectives for information technology. The transistor is presented in Advanced Materials.

Digitization results in a high energy consumption...

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Toward a Universal Quantum Computer

This is a nitrogen-vacancy (NV) center in diamond with two crossed wires for holonomic quantum gates over the geometric spin qubit with a polarized microwave. Credit: Image courtesy of Yokohama National University

This is a nitrogen-vacancy (NV) center in diamond with two crossed wires for holonomic quantum gates over the geometric spin qubit with a polarized microwave. Credit: Image courtesy of Yokohama National University

Researchers show holonomic quantum gates under zero-magnetic field at room temperature, which will enable the realization of fast and fault-tolerant universal quantum computers. A quantum computer is a powerful machine with the potential to solve complex problems much faster than today’s conventional computer can. Researchers are currently working on the next step in quantum computing: building a universal quantum computer.

The paper, published in the journal Nature Communications, reports experimental demonstration of non-adiabatic and non-abelian holonomic quantum gates over a ...

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Unraveling the Nature of ‘Whistlers’ from Space in the Lab

Scientists at the University of California, Los Angeles present research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets of radio waves that race along magnetic field lines. Appearing in the Physics of Plasmas, the study provides new insights into the nature of whistlers and space plasmas and could one day aid in the development of practical plasma technologies with magnetic fields, including spacecraft thrusters that use charged particles as fuel. This image shows the growth of a whistler mode with circular phase front and cross-field propagation.

Scientists at the University of California, Los Angeles present research on a curious cosmic phenomenon known as “whistlers” — very low frequency packets of radio waves that race along magnetic field lines. Appearing in the Physics of Plasmas, the study provides new insights into the nature of whistlers and space plasmas and could one day aid in the development of practical plasma technologies with magnetic fields, including spacecraft thrusters that use charged particles as fuel. This image shows the growth of a whistler mode with circular phase front and cross-field propagation.

A new study sheds light on how ultralow frequency radio waves and plasmas interact...

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