McRae Andrew C, Wei Guoqing, Huang Linxiang, Yigen Serap, Tayari Vahid, Champagne Alexandre R
Department of Physics, Concordia University, Montréal, Québec, H4B 1R6, Canada.
Adv Mater. 2024 Jun;36(23):e2313629. doi: 10.1002/adma.202313629. Epub 2024 Apr 16.
2D materials (2DMs) are fundamentally electro-mechanical systems. Their environment unavoidably strains them and modifies their quantum transport properties. For instance, a simple uniaxial strain can completely turn off the conductance of ballistic graphene or switch on/off the superconducting phase of magic-angle bilayer graphene. This article reports measurements of quantum transport in strained graphene transistors which agree quantitatively with models based on mechanically-induced gauge potentials. A scalar potential is mechanically induced in situ to modify graphene's work function by up to 25 meV. Mechanically generated vector potentials suppress the ballistic conductance of graphene by up to 30% and control its quantum interferences. The data are measured with a custom experimental platform able to precisely tune both the mechanics and electrostatics of suspended graphene transistors at low-temperature over a broad range of strain (up to 2.6%). This work opens many opportunities to harness quantitative strain effects in 2DM quantum transport and technologies.
二维材料(2DMs)本质上是机电系统。它们所处的环境不可避免地会使它们产生应变,并改变其量子输运特性。例如,简单的单轴应变可以完全关闭弹道石墨烯的电导,或者开启/关闭魔角双层石墨烯的超导相。本文报道了应变石墨烯晶体管中量子输运的测量结果,这些结果与基于机械诱导规范势的模型在定量上相符。通过原位机械诱导产生一个标量势,可将石墨烯的功函数改变高达25毫电子伏特。机械产生的矢量势可将石墨烯的弹道电导抑制高达30%,并控制其量子干涉。这些数据是使用一个定制的实验平台测量的,该平台能够在低温下、在很宽的应变范围(高达2.6%)内精确调节悬浮石墨烯晶体管的力学和静电学特性。这项工作为利用二维材料量子输运和技术中的定量应变效应开辟了许多机会。