Quantised conductance of one-dimensional strongly-correlated electrons in a ZnO heterostructure

ORAL

Abstract

Oxide heterostructures are versatile platforms with which to research and create novel functional nanostructures. We have developed one-dimensional (1D) quantum-wire devices using quantum point contacts on MgZnO/ZnO heterostructures and observe ballistic electron transport with conductance quantised in units of 2e2/h. Using DC-bias and in-plane-field measurements, we find that the g-factor is enhanced to around 6.8, more than three times the value in bulk ZnO. We show that the effective mass m* increases as the electron density decreases, resulting from the strong electron-electron interactions. In this strongly interacting 1D system we study features matching the '0.7' conductance anomalies up to the fifth subband. We demonstrate that high-mobility oxide heterostructures such as this can provide good alternatives to conventional III-V semiconductors in spintronics and quantum computing as they do not have their unavoidable dephasing from nuclear spins. This paves a way for the development of qubits benefiting from the low defects of an undoped heterostructure together with the long spin lifetimes achievable in silicon.

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Presenters

  • Christopher J Ford

    Cavendish Laboratory, University of Cambridge, University of Cambridge, Department of Physics, University of Cambridge

Authors

  • Hangtian Hou

    University of Cambridge, Department of Physics, University of Cambridge

  • Yusuke Kozuka

    National Institute for Materials Science, Research Center for Magnetic and Spintronic Materials, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba 305-0047, Japan

  • Jun-wei Liao

    University of Cambridge

  • Luke W Smith

    University of Cambridge

  • Dean Kos

    University of Cambridge

  • Jonathan Griffiths

    University of Cambridge, Department of Physics, University of Cambridge, Physics, Cambridge University

  • Joseph Falson

    Max-Planck Institute, Max Planck Institute for Solid State Research, Max Planck Institute for Solid State Research, D-70569 Stuttgart, Germany

  • Atsushi Tsukazaki

    Tohoku University, Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan, IMR Tohoku University, IMR, Tohoku Univ., Institute for Materials Research, Tohoku University

  • Masashi Kawasaki

    The University of Tokyo, Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), The University of Tokyo, Tokyo 113-8656, Japan, University of Tokyo, Applied Physics and QPEC, University of Tokyo, Department of applied physics, The University of Tokyo, Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), the University of Tokyo, Department of Applied Physics and Quantum-Phase Electronics Center (QPEC), Univ. of Tokyo, Tokyo, Japan.

  • Christopher J Ford

    Cavendish Laboratory, University of Cambridge, University of Cambridge, Department of Physics, University of Cambridge