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Towards coupled valley qubits in silicon

ORAL

Abstract

Valley states in silicon are a promising candidate for encoding qubits in gate-defined quantum dots due to their protection against charge noise, fast operation times, and ability to operate without a magnetic field. Recently, two-axis quantum control of a valley qubit using gate pulse sequences with X and Z rotations, occurring within a fast operation time of 300 ps, has been demonstrated [1]. In this talk, we present our progress on coupling two such valley qubits. We have fabricated a device consisting of two double-quantum dots on a SiGe heterostructure for our experiments. We further measure the capacitive coupling between the two double dots in the few electron region, showing sufficiently large and tunable coupling. By exploiting this electrostatic interaction, we discuss our plan for employing the two coupled valley qubits to realize a two-qubit logic gate.

[1] Nicholas E. Penthorn, Joshua S. Schoenfield, John D. Rooney, Lisa F. Edge, and HongWen Jiang, “Two-axis quantum control of a fast valley qubit in silicon”, npj Quantum Information, in press (2019).

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Presenters

  • John Rooney

    California State University, Los Angeles, University of California, Los Angeles

Authors

  • John Rooney

    California State University, Los Angeles, University of California, Los Angeles

  • Blake M Freeman

    University of California, Los Angeles

  • Nicholas Penthorn

    Physics and Astronomy, University of California, California State University, Los Angeles, University of California, Los Angeles

  • Lisa F Edge

    HRL, HRL laboratories, LLC, 3011 Malibu Canyon Road, Malibu, CA 90265, USA, HRL Laboratories, HRL Laboratories LLC, 3011 Malibu Canyon Road, Malibu, California 90265, USA, HRL Laboratories, LLC

  • HongWen Jiang

    Physics and Astronomy, University of California, California State University, Los Angeles, University of California, Los Angeles