Atomically-Thin, twisted Graphene has unique properties that could advance quantum computing


SOURCE: CALIFORNIANEWSTIMES.COM
SEP 12, 2021

A new collaborative study describes how electrons move through two different configurations of two-layer graphene, which is in the form of atomically thin carbon. These results provide insights that researchers can use to design more powerful and secure quantum computing platforms in the future.

Researchers explain how electrons move in two-dimensional layers Graphene, Findings that may lead to future design progress Quantum computing platform.

New research published in Physical review letter Describes how electrons move through two different configurations of two-layer graphene, which is an atomically thin form of carbon.This study was conducted at Brookhaven National Laboratory, University of Pennsylvania, New Hampshire University, Stony Brook University, and Columbia UniversityProvides insights that researchers can use to design more powerful and secure quantum computing platforms in the future.

“Today’s computer chips are based on knowledge of how electrons move in semiconductors, especially silicon,” said Zhongwei Dai, the first co-author of a Brookhaven postdoc. “But the physical properties of silicon are reaching their physical limits in how small transistors can be made and how many can fit on a chip. Quantum is shrinking in two-dimensional materials. Understanding how it works on a small scale of a few nanometers in another dimension could unleash another way to use electrons in quantum information science. “

When a material is designed to a size of a few nanometers on these small scales, the electrons are confined in a space of the same dimensions as its own wavelength, and the overall electronic and optical properties of the material are a process that follows: It changes with. Quantum confinement. In this study, researchers used graphene to study these confinement effects on both electrons and photons, or particles of light.

This work relied on two independently developed advances in Penn and Brookhaven. Pen researchers, including former postdoctoral fellow Zhaoli Gao in Charlie Johnson’s lab, currently enrolled at the Chinese University of Hong Kong, used their own gradients-alloy A growth substrate for growing graphene with three different domain structures: single layer, Bernal stack double layer, and twisted double layer. Next, the graphene material was transferred to a special substrate developed in Brookhaven. This allowed researchers to investigate both the electronic and optical resonances of the system.

“This is a great collaboration,” says Johnson. “By combining the great features of Brookhaven and the pen, we can make important measurements and discoveries that none of us can do on our own.”

Researchers have been able to detect both electronic and optical interlayer resonances, and have found that in these resonance states, electrons move back and forth across the 2D interface at the same frequency. Their results also suggest that the distance between the two layers increases significantly in a twisted configuration, which affects how electrons move due to interlayer interactions. They also found that twisting one of the graphene layers by 30 ° shifts the resonance to lower energies.

“Devices made of rotated graphene can have very interesting and unexpected properties due to the large spacing between electrons that can move,” said Julek Sadowski, co-author of Brookhaven. increase.

In the future, researchers will use twisted graphene to build new devices, and at the same time, based on the results of this study, adding various materials to the layered graphene structure will result in downstream electronic and optical properties. See how it affects you.

“We look forward to continuing to work with our Brookhaven colleagues at the forefront of the application of 2D materials in quantum science,” says Johnson.

See also: “Quantum well bound state of graphene heterostructure interface” by Zhongwei Dai, Zhaoli Gao, Sergey S. Pershoguba, Nikhil Tiwale, Ashwanth Subramanian, Qicheng Zhang, Calley Eads, Samuel A. Tenney, Richard M. Osgood, Chang-Yong Nam, Zhaoli Gao, AT Charlie Johnson and Jersey T. Sadowski, August 20, 2021 Physical review letter..
DOI: 10.1103 / PhysRevLett.127.086805

The complete list of co-authors includes Zhaoli Gao (now the Chinese University of Hong Kong), Qicheng Zhang, and Charlie Johnson of the University of Pennsylvania. Brookhaven Zhongwei Dai, Nikhil Tiwale, Calley Eads, Samuel A. Tenney, Chang-Yong Nam, Jerzy T. Sadowski. Sergey S. Pershogub and Jiadong Zang of the University of New Hampshire. Ashwanth Subramanian of Stony Brook University; Richard M. Osgood of Columbia University.

Charlie Johnson is Professor Rebecca W. Bushnell of the Department of Physics and Astronomy, Faculty of Arts and Sciences, University of Pennsylvania.

This study is supported by National Science Foundation grants MRSECDMR-1720530 and EAGER1838412. Brookhaven National Laboratory is supported by the US Department of Energy’s Department of Science.

Atomically-Thin, Twisted Graphene Has Unique Properties That Could Advance Quantum Computing Source link Atomically-Thin, Twisted Graphene Has Unique Properties That Could Advance Quantum Computing

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