Measurements of capacitive coupling in two double dots in Si/SiGe for application in two qubit gates

ORAL

Abstract

We present measurements of a Si/SiGe quantum dot device made with overlapping self-oxidized Al gates. The device includes a linear array of four quantum dots and two auxiliary dots for charge sensing. The dots have a lithographic pitch of 130 nm and are separated from the gates by a 30 nm SiGe spacer and 5 nm of aluminum oxide deposited by ALD. We measure the charge noise in all six dots and observe a power spectral density that is approximately 1/f in the 1-200 Hz range with a chemical potential noise amplitude of 1-2 μeV/Hz1/2 at 1 Hz. We tune the device to form two tunnel-coupled double dots and observe the capacitive coupling with both double dots at the (0,1)-(1,0) polarization line. We measure a detuning shift of ~8 GHz due to the change in polarization of the adjacent double dot, demonstrating the potential of the system for coherent two-qubit coupling via capacitive interaction.

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Presenters

  • Samuel Neyens

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

Authors

  • Samuel Neyens

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

  • Evan R MacQuarrie

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

  • John Dodson

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

  • Nathan Holman

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

  • Brandur Thorgrimsson

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

  • Thomas McJunkin

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

  • Joelle Corrigan

    • Department of Physics, University of Wisconsin-Madison

  • Mario Palma

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

  • Lisa Edge

    • HRL Laboratories, LLC

  • Mark G Friesen

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

  • Susan Coppersmith

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

  • Mark Alan Eriksson

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