We demonstrate a flip-chip device for performing low-temperature acoustoelectric measurements on exfoliated two-dimensional materials. With this device, we study gate-tunable acoustoelectric transport in an exfoliated monolayer graphene device, measuring the voltage created as high-frequency surface acoustic waves dynamically drive the graphene charge carriers, the density of which we simultaneously control with a silicon back-gate. We demonstrate ambipolar dependence of the acoustoelectric signal, as expected from the sign of the graphene charge carriers. We observe a marked reduction in the magnitude of the acoustoelectric signal over a well-defined range of density in the vicinity of charge neutrality, which we attribute to a spatially heterogeneous charge-disorder landscape not directly revealed by conventional transport measurements.
@article{arxiv.1801.05270,
title = {Flip-chip gate-tunable acoustoelectric effect in graphene},
author = {J. R. Lane and L. Zhang and M. A. Khasawneh and B. N. Zhou and E. A. Henriksen and J. Pollanen},
journal= {arXiv preprint arXiv:1801.05270},
year = {2018}
}