APS Logo

Improving Gate Dielectrics for Reducing Charge Noise in Si/SiGe Quantum Dots

ORAL

Abstract

We report on the materials development of a novel low temperature SiO2 gate dielectric for use in Si/SiGe quantum dot devices. X-ray Photoemission Spectroscopy (XPS) measurements show nitric acid oxidation of silicon (NAOS) or silicon-germanium alloys produces a more stoichiometric and thicker silicon oxide over other low temperature techniques [1]. Using this approach, we create a ~1.7 nm SiO2 gate dielectric over the active region of a Si/SiGe quantum dot device coupled to a Nb microwave resonator for charge state readout. By measuring the current noise in a quantum dot we observe a 1/f power spectral density of chemical potential noise with an amplitude of 0.203 μeV2/Hz at 1 Hz which compares favorably to similar devices using ALD Al2O3 and native SiO2 [2]. Further, we demonstrate low frequency Landau-Zener spectroscopy of a double dot charge qubit and discuss cavity-charge coupling experiments [3,4].

References:
[1] H. Kobayashi et al. Applied Surface Science 256 (19) 5744 (2010).
[2] E. J. Connors et al. Preprint at https://arxiv.org/abs/1907.07549
[3] S. N. Shevchenko et al. PRB 98, 195434 (2018)
[4] X. Mi et al. Phys. Rev. B 98, 161404 (2018)

–

Presenters

  • Nathan Holman

    University of Wisconsin - Madison, Department of Physics, University of Wisconsin-Madison, Madison WI, USA

Authors

  • Nathan Holman

    University of Wisconsin - Madison, Department of Physics, University of Wisconsin-Madison, Madison WI, USA

  • John Dodson

    University of Wisconsin - Madison

  • Evan MacQuarrie

    University of Wisconsin - Madison

  • 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

  • Robert F McDermott

    University of Wisconsin - Madison, Department of Physics, University of Wisconsin-Madison, Madison WI, USA, Physics, University of Wiconsin - Madison

  • Susan Nan Coppersmith

    University of Wisconsin - Madison, University of New South Wales, Sydney, Australia, Department of Physics, University of Wisconsin-Madison, University of Wisconsin-Madison, University of New South Wales, University of Wisconsin-Madison, The University of New South Wales

  • Mark G Friesen

    University of Wisconsin - Madison, Department of Physics, University of Wisconsin-Madison, Madison WI, USA, University of Wisconsin-Madison

  • Mark Alan Eriksson

    University of Wisconsin - Madison, Physics, University of Wisconsin - Madison, Madison, WI USA, Department of Physics, University of Wisconsin-Madison, Madison WI, USA, Department of Physics, University of Wisconsin-Madison, Madison, WI 53706, USA, University of Wisconsin-Madison