Comparison of Dynamical Decoupling Schemes in Double Quantum Dot Spin Qubits

ORAL

Abstract

The decoherence and decoupling of a Singlet-Triplet spin qubit in a GaAs double quantum dot are studied, employing high-fidelity repeated single-shot readout of the charge arrangement with less than 1 $\mu$s repetition period. Coherence times of greater than $100~\mu$s are obtained for both Carr Purcell and Concatenated Dynamical Decoupling, opening the way for future fault tolerant error correction algorithms. In addition, long operation sequences combining single qubit gates and decoupling schemes are studied. Nuclear polarization build-up and feedback mechanisms are investigated and combined with single-shot measurement and control.

*Support from ARO/iARPA, Department of Defense, IBM, and the NSF-NNIN through Harvard's Center for Nanoscale Systems.

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Authors

  • Christian Barthel

    • Department of Physics, Harvard University

  • James Medford

    • Department of Physics, Harvard University

  • Hendrik Bluhm

    • Department of Physics, Harvard University

  • Charles Marcus

    • Department of Physics, Harvard University

  • Micah Hanson

    • Materials Department, University of California, Santa Barbara

  • Arthur Gossard

    • Materials Department, University of California, Santa Barbara