InAsSb Quantum Wells for Topological Quantum Computation

ORAL

Abstract

Recent advances in coupling superconductivity to near surface InAs quantum wells (QWs) have allowed for the first observation of Majorana Zero Modes on a scalable platform paving the way for lithographically defined complex networks necessary for topological quantum computation. Increase in spin-orbit coupling should lead to an increase in induced topological gap and topological protection. InAsSb may have a higher spin-orbit coupling than both InAs and InSb. In this work, near surface InAs(x)Sb(1-x) quantum wells, with varying As/Sb ratio and varying depth from the surface have been demonstrated. Formation of a near surface 2DEG in InAs is aided by presence of a surface accumulation layer, while Fermi level pinning within the band gap of InSb inhibits this. As/Sb ratio in InAsSb can in principle be used to tune the surface pinning. Magneto-transport of InAs(0.2)Sb(0.8) QWs at 2K indicates the presence of a surface depletion layer deduced by a reduction in dopant ionization efficiency with reducing depth from the surface. This work is expected to aid in providing a direct control over the coupling of superconductivity from an in-situ grown epitaxial Aluminum layer through a ‘tuned’ tunnel barrier while setting up a new platform for robust induced topological superconductivity.

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Presenters

  • Mihir Pendharkar

    University of California Santa Barbara, Department of Electrical and Computer Engineering, University of California, Santa Barbara, University of California - Santa Barbara, Univ of California - Santa Barbara

Authors

  • Mihir Pendharkar

    University of California Santa Barbara, Department of Electrical and Computer Engineering, University of California, Santa Barbara, University of California - Santa Barbara, Univ of California - Santa Barbara

  • Joon Sue Lee

    University of California Santa Barbara, California NanoSystems Institute, University of California, Santa Barbara, University of California - Santa Barbara, Materials Science, University of California - Santa Barbara, Univ of California - Santa Barbara

  • Chris Palmstrom

    University of California Santa Barbara, Materials Department, California NanoSystems Institute, Electrical and Computer Engineering, University of California, University of California-Santa Barbara, California Nanosystems Institute, Dept. of Electrical and Computer Engineering, and Dept. of Materials, Univ of California - Santa Barbara, University of California - Santa Barbara, Electronics & Computer Enginneering, University of California Santa Barbara, Materials Department, University of California, Santa Barbara, Materials, University of California Santa Barbara, Univ of California - Santa Barbara