Acoustically-induced pseudo-gauge fields and anomalous transport phenomena in graphene

We will show that acoustically stimulated carrier transport in graphene at 4 Kelvin signals the presence of artificial gauge fields through the build-up of a transversal voltage at zero magnetic field. We fabricated a graphene Hall bar on a hybrid piezoelectric LiNbO₃ on insulator substrate. A nearby interdigitated transducer (IDT) can launch a surface acoustic wave (SAW) that acoustically accelerates the carriers in the graphene layer. The propagating SAW induces an acoustic current. At zero magnetic field, we observe acoustically-induced synthetic Hall voltages, depending on the carrier type, concentration and the SAW power. The synthetic Hall voltage can modulate a conventional Hall voltage arising in a large external magnetic field. Our observation is consistent with studies of strain-induced pseudo-gauge fields. [1] We developed a model that successfully maps the mechanical deformation within the graphene, precipitated by the SAW in the substrate, to the presence of a gauge field and the observed synthetic Hall voltage. [2]