Fabry-Pérot interference in 2D low-density Rashba gas

¹ College of Science, Nanjing University of Aeronautics and Astronautics - Nanjing 210016, China
² National Laboratory of Solid State Microstructures and School of Physics, Nanjing University Nanjing, 210093, China
³ School of Science, Jiangxi University of Science and Technology - Ganzhou 341000, China
⁴ Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, GPETR Center for Quantum Precision Measurement, SPTE, South China Normal University - Guangzhou 510006, China
⁵ Collaborative Innovation Center of Advanced Microstructures, Nanjing University - Nanjing 210093, China

^(a) yuanqiaoli2014@163.com (corresponding author)
^(c) jxluow@163.com
^(d) pchenweis@gmail.com

Received: 16 June 2021
Accepted: 9 February 2022

Abstract

In mesoscopic electronic systems, the Fabry-Pérot (FP) oscillation is observed in various 1D devices. As for higher dimensions, numerous transverse channels usually lead to dephasing that quenches the overall oscillation of the conductance. Up to now, the FP oscillation in 2D electronic systems is only reported in graphene-based devices and very recently, the pn junctions of inverted InAs/GaSb double quantum well (Karalic M. et al., Phys. Rev. X, 10 (2020) 031007). In the latter, the band shape of a sombrero hat plays an essential role, which introduces a novel mechanism of electron-hole hybridization for the 2D FP oscillation. In this work, we propose that such a scenario can be generalized to the 2D planar junction composed of low-density Rashba gas, where the band bottom possesses sombrero hat shape as well. We show that the backscattering between the outer and inner Fermi circles dominates the FP interference and significantly suppresses the dephasing effect between different transverse channels, which leads to a visible oscillation of the tunneling conductance. In particular, the visibility of the oscillating pattern can be enhanced by applying interface barriers, which is in contrast to that in the InAs/GaSb double quantum well. Our results provide a promising way for the implementation of the FP oscillation in the 2D electron gas.