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HL: Fachverband Halbleiterphysik
HL 3: Focus Session: Progress in Hybrid Phononic Quantum Technologies I
HL 3.3: Talk
Monday, March 27, 2023, 10:30–10:45, POT 151
Acoustically-induced pseudo-gauge fields and anomalous transport phenomena in graphene — •Pai Zhao1, Lars Tiemann1, Lev Mourokh2, Vadim M. Kovalev3, and Robert H. Blick1 — 1University of Hamburg, Germany — 2Department of Physics, Queens College, New York, USA — 3Novosibirsk, Russia
One of many remarkable consequences of the low-energy Dirac description of graphene is the emergence of synthetic gauge fields under lattice deformation that affect the carrier dynamics. We 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 gate-tunable, large-scale CVD graphene Hall bar on a hybrid piezoelectric LiNbO3 on insulator substrate. An interdigitated transducer launches a surface acoustic wave (SAW) that acoustically accelerates the carriers in the graphene. At zero magnetic field, we observe large anomalous acoustically-induced synthetic Hall voltages up to 200 µV, depending on the carrier type, concentration and SAW power. The synthetic Hall voltage can modulate a conventional Hall voltage arising in a large external magnetic field [1]. Our observation is consistent with studies of strain-induced pseudo-gauge fields [2-4].
[1] P. Zhao et al., Phys. Rev. Lett. 128, 256601 (2022); [2] N. Levy et al., Science 329, 544 (2010); [3] F. Guinea, M. I. Katsnelson and A. K. Geim, Nat. Phys. 6, 30 (2010); [4] M. Oliva-Leyva and G. G. Naumis, J. Phys.: Condens. Matter 28, 025301 (2015).