Light-mass hole-spins in a Ge quantum well as qubits

ORAL

Abstract

Electrons bound to quantum dots provide well defined (spin 1/2) physical qubits. Under strong spin-orbit coupling spin qubits are expected to suffer rapid dephasing from charge noise; however, recent experiments have effectively employed spin-orbit coupling in coherent quantum gates. Here we show that hole spins in a Si1-xGex/Ge/ Si1-xGex quantum well possess highly desirable properties as qubits, including a high natural abundance of nuclear spin-0 isotopes, a large (~100 meV) intrinsic splitting between the light and heavy hole bands, and a very light (~0.05m0) effective mass. We employ ab initio methods to determine the band structure of strained Ge quantum wells as a function of x, and we discuss the advantages and challenges of using Ge hole spins as qubits.

*This work was supported in part by ARO (W911NF-17-1-0274), NSF (OISE-1132804), and the Vannevar Bush Faculty Fellowship program sponsored by the Basic Research Office of the Assistant Secretary of Defense for Research and Engineering and funded by the Office of Naval Research through grant N00014-15-1-00

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Presenters

  • Rodrigo Capaz

    • Univ Fed Rio de Janeiro

Authors

  • Rodrigo Capaz

    • Univ Fed Rio de Janeiro

  • Luis Terrazos

    • Univ Fed Campina Grande

  • Andre Saraiva

    • Instituto de Fisica, Universidade Federal do Rio de Janeiro
    • Univ Fed Rio de Janeiro

  • Mark Friesen

    • Physics, University of Wisconsin-Madison
    • Univ of Wisconsin, Madison
    • University of Wisconsin-Madison
    • Department of Physics, Univ of Wisconsin, Madison
    • Department of Physics, University of Wisconsin - Madison
    • Department of Physics, University of Wisconsin-Madison
    • Physics, Univ of Wisconsin, Madison

  • Susan Coppersmith

    • Physics, University of Wisconsin-Madison
    • Univ of Wisconsin, Madison
    • University of Wisconsin-Madison
    • Physics, University of Wisconsin: Madison
    • Department of Physics, Univ of Wisconsin, Madison
    • Department of Physics, University of Wisconsin - Madison
    • Department of Physics, University of Wisconsin-Madison
    • Physics, Univ of Wisconsin, Madison

  • Belita Koiller

    • Instituto de Fisica, Universidade Federal do Rio de Janeiro
    • Univ Fed Rio de Janeiro