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Dominant scattering mechanisms in InSbAs quantum wells: a promising platform for topological superconductivity

ORAL

Abstract

The two-dimensional electron gas (2DEG) confined in InSb1−xAsx quantum wells is a promising platform to explore topological superconductivity when coupled to a s-wave superconductor due to its higher effective g-factor and stronger spin-orbit coupling compared to commonly used binary InSb and InAs. Stable mesoscopic device operation and low disorder are two desired properties needed for the exploration of topological superconductivity. We report on material quality and dominant scattering mechanisms in a series of 30 nm quantum wells with arsenic mole fractions of x = 0.05, 0.13, and 0.19. Peak mobility at a density of ∼ 2.5 × 1011 cm−2 is 2.4, 2.0 and 1.4 × 105 cm−2/Vs respectively. For samples with x = 0.13 and 0.19, we find a weak dependence of mobility on 2DEG density, suggesting that short-range scattering limits mobility at arsenic concentrations above ∼ x=0.1. The data indicate that alloy disorder is the main source of short-range scattering; an alloy scattering rate of τalloy = 45 nm−1 per % As is extracted. This parameter is important for considerations of impact of disorder on induced superconductivity. We also present data on mesoscopic devices, including analysis of charge noise, drift, and hysteresis at T=0.3K.

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Presenters

  • Sara Metti

    Elmore Family School of Electrical and Computer Engineering and Birck Nanotechnology Center, Purdue University

Authors

  • Sara Metti

    Elmore Family School of Electrical and Computer Engineering and Birck Nanotechnology Center, Purdue University

  • Candice Thomas

    Purdue University, Department of Physics and Astronomy, Purdue University, Department of Physics and Astronomy, Purdue University,, Department of Physics and Astronomy and Birck Nanotechnology Center, Purdue University

  • Di Xiao

    Department of Physics and Astronomy and Birck Nanotechnology Center, Purdue University

  • Michael J Manfra

    Purdue University, Microsoft Quantum Purdue, Purdue University, Birck Nanotechnology Center, Purdue University, West Lafayette, IN, USA; Microsoft Quantum Lab, Purdue University, West Lafayette, IN, USA, Physics and Astronomy, Purdue University, Department of Physics and Astronomy, Birck Nanotechnology Center, School of Electrical and Computer Engineering and Microsoft Quantum Lab West Lafayette, Purdue University, Department of Physics and Astronomy and Nanotechnology Center Purdue University, Microsoft Quantum Lab West Lafayette, Department of Physics and Astronomy, Birck Nanotechnology Center, School of Materials Engineering and School of Electrical and Computer Engineering, Purdue University