Two-axis Control and Readout of an Exchange-Only Spin Qubit in a GaAs Triple Quantum Dot

ORAL

Abstract

The initialization, full control, and readout of a GaAs triple quantum dot exchange qubit is demonstrated. Appropriate depletion gate design has enabled control and single-shot readout along multiple Bloch sphere axes in a three electron device. Rotations around both non-orthogonal control axes are projected along three separate Bloch sphere axes, and quality factors $(Q \equiv \omega / T_2^*)$ of 500 are observed. Finally, we analyze decoherence and dynamical decoupling schemes unique to this system.

*Support from IARPA MQCO, DARPA QuEST, and NSF Materials World Network.

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Authors

  • J. Medford

    • Harvard University

  • J.M. Taylor

    • Joint Quantum Institute, NIST

  • B.D. Armstrong

    • Harvard University

  • D.P. DiVincenzo

    • RWTH Aachen

  • C.M. Marcus

    • Harvard University, Niels Bohr Institute, University of Copenhagen

  • H. Lu

    • Materials Department, University of California, Santa Barbara

  • A.C. Gossard

    • Materials Department, University of California, Santa Barbara