Quantum Transport Strain Engineering in Graphene

We measure ballistic charge conductivity in strained suspended graphene and observe theoretically predicted strain-induced scalar and vector potentials. To do so, we built an experimental platform for quantum transport strain engineering in 2D materials. This instrumentation permits low temperature (0.3 K- 70 K) transport and a tunable uniaxial strain (up to 3%) which is independent from the gate-tunable charge density. We show slippage-free clamping of high aspect-ratio graphene crystals where atomically ordered edges are unnecessary for quantitative straintronics. We perform in-depth study of transport in a graphene channel with length 90 nm and width 600 nm. We observe ballistic transport in both the naked graphene channel and metal-film-coated graphene contacts. Through the strain-induced scalar potential, we can down shift the low energy band structure of the graphene channel by 20 meV. We also clearly observe the effect of a gauge vector potential, which reversibly suppresses the conductance by up to 13.6%