Mechanical control of quantum transport in graphene

Abstract

Two-dimensional materials (2DMs) are fundamentally electro-mechanical systems. Their environment unavoidably strains them and modifies their quantum transport properties. For instance, a simple uniaxial strain could completely turn off the conductivity of ballistic graphene or switch on/off the superconducting phase of magic-angle bilayer graphene. Here we report measurements of quantum transport in strained graphene which agree quantitatively with models based on mechanically-induced gauge potentials. We mechanically induce in-situ a scalar potential, which modifies graphene's work function by up to 25 meV, and vector potentials which suppress the ballistic conductivity of graphene by up to 30 % and control its quantum interferences. To do so, we developed an 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 experimentally explore quantitative strain effects in 2DM quantum transport and technologies.