valleytronics tagged posts

Odds are good for Unique 2D Compound

The polarized light emission from a 7-layer cesium, bismuth and iodine triangle developed at Rice University, under circularly polarized excitation, shows the valleytronics mechanism in action. The inset shows the electronic state written and read optically in a valleytronic memory. Courtesy of the Lou Group

Perovskites show potential for valleytronics applications. Engineers at Rice University and Texas A&M University have found a 2D material that could make computers faster and more energy-efficient.

Their material is a derivative of perovskite — a crystal with a distinctive structure — that has the surprising ability to enable the valleytronics phenomenon touted as a possible platform for information processing and storage.

The lab of materials scientist Jun Lou of Rice’s Brow...

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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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Scientists discover ‘Chiral Phonons’ – Atomic Rotations in a 2D Semiconductor Crystal

This diagram maps out atomic motion in separate phonon modes. At left ("LO" represents a longitudinal optical mode), selenium atoms exhibit a clockwise rotation while tungsten atoms stand still. At right ("LA" represents a longitudinal acoustic mode), tungsten atoms exhibit a clockwise rotation while selenium atoms rotate in a counterclockwise direction. Credit: Hanyu Zhu, et al.

This diagram maps out atomic motion in separate phonon modes. At left (“LO” represents a longitudinal optical mode), selenium atoms exhibit a clockwise rotation while tungsten atoms stand still. At right (“LA” represents a longitudinal acoustic mode), tungsten atoms exhibit a clockwise rotation while selenium atoms rotate in a counterclockwise direction. Credit: Hanyu Zhu, et al.

Experiments confirm the first chiral phonon that could enable exotic forms of electronics. Berkeley Lab has found the first evidence that a shaking motion in the structure of an atomically thin (2D) material possesses a naturally occurring circular rotation...

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