Researchers describe how electrons move through two-dimensional layered graphene 0 findings that could lead to advances in the design of future quantum computing platforms.

New research published in Physical Review Letters describes how electrons move through two different configurations of bilayer graphene, the atomically-thin form of carbon. This study, the result of a collaboration between Brookhaven National Laboratory, the University of Pennsylvania, the University of New Hampshire, Stony Brook University, and Columbia University 0 provides insights that researchers could use to design more powerful and secure quantum computing platforms in the future.

“Today’s computer chips are based on our knowledge of how electrons move in semiconductors, specifically silicon,” says first and co-corresponding author Zhongwei Dai, a postdoc at Brookhaven. “But the physical properties of silicon are reaching a physical limit in terms of how small transistors can be made and how many can fit on a chip. If we can understand how electrons move at the small scale of a few nanometers in the reduced dimensions of 2-D materials, we may be able to unlock another way to utilize electrons for quantum information science.”

Circa 2019

LONDON — A laboratory in Switzerland has found a way of using a laser to change and regulate the polarization, wavelength and intensity of light in “excitons” in 2D materials, creating the potential for a new generation of transistors with less energy loss and heat dissipation, opening up the potential for low-power quantum computing.

Excitons are created when an electron absorbs light and moves into a higher energy level, or “energy band” as it is called in solid quantum physics. This excited electron leaves behind an “electron hole” in its previous energy band. And because the electron has a negative charge and the hole a positive charge, the two are bound together by an electrostatic force called a Coulomb force. It’s this electron-electron hole pair that is referred to as an exciton.

Scientists from EPFL’s Laboratory of Nanoscale Electronics and Structures (LANES) had already developed a method to control exciton flows at room temperature last year. In the latest development, they have discovered new properties of these quasiparticles that can lead to more energy-efficient electronic devices and have found a way to control some of the properties and change the polarization of the light they generate. The scientists’ discovery forms part of a relatively new field of research called valleytronics and has just been published in Nature Photonics.