Gate-tunable quantum acoustoelectric transport in graphene

• Published in: arXiv.org 2024-03
• Main Authors: Mou, Yicheng, Chen, Haonan, Liu, Jiaqi, Lan, Qing, Wang, Jiayu, Zhang, Chuanxin, Wang, Yuxiang, Gu, Jiaming, Zhao, Tuoyu, Jiang, Xue, Wu, Shi, Zhang, Cheng
• Format: Article
• Language: English
• Subjects: Carrier density; Elementary excitations; Graphene; Lithium niobates; Magnetic fields; Nanotechnology devices; Oscillations; Piezoelectricity; Substrates; Surface acoustic waves
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2403.20248

Transport probes the motion of quasiparticles in response to external excitations. Apart from the well-known electric and thermoelectric transport, acoustoelectric transport induced by traveling acoustic waves has been rarely explored. Here, by adopting a hybrid nanodevices integrated with piezoelectric substrates, we establish a simple design of acoustoelectric transport with gate tunability. We fabricate dual-gated acoustoelectric devices based on BN-encapsuled graphene on LiNbO3. Longitudinal and transverse acoustoelectric voltages are generated by launching pulsed surface acoustic wave. The gate dependence of zero-field longitudinal acoustoelectric signal presents strikingly similar profiles as that of Hall resistivity, providing a valid approach for extracting carrier density without magnetic field. In magnetic fields, acoustoelectric quantum oscillations appear due to Landau quantization, which are more robust and pronounced than Shubnikov-de Haas oscillations. Our work demonstrates a feasible acoustoelectric setup with gate tunability, which can be extended to the broad scope of various Van der Waals materials.