APS Logo

Coherent spectroscopy of a Si/SiGe double quantum dot molecule

ORAL

Abstract

We report the wideband microwave spectroscopy of a gate-defined double quantum dot qubit. The double quantum dot, operated with a total of five electrons, has a series of molecular energy levels that can be manipulated coherently. Working in the (4,1)-(3,2) charge configuration, we use a two-step Ramsey pulse sequence to characterize the energy levels of the (3,2) charge configuration as a function of the double-dot detuning. Using this procedure, we demonstrate differences in the dispersion for two closely spaced levels (<2GHz separation in energy). We present measurements of the broadband spectrum, discovering seven energy levels that can be addressed coherently, each with distinct Rabi oscillation characteristics. The double quantum dot is formed in an undoped Si/SiGe heterostructure using an overlapping gate architecture [1]. The measurements are acquired using a tunable latched measurement scheme similar to that in Ref. [2], made possible by the presence of independent reservoirs and corresponding tunnel barriers for each quantum dot.

[1] Zajac, D. et al., Appl. Phys. Lett. 106, 223507 (2015)
[2] S. A. Studenikin et al. Appl. Phys. Let., 101, 23 (2012)

–

Presenters

  • Joelle Baer

    University of Wisconsin - Madison

Authors

  • Joelle Baer

    University of Wisconsin - Madison

  • John Dodson

    University of Wisconsin - Madison

  • Brandur Thorgrimsson

    University of Wisconsin - Madison

  • Ekmel Ercan

    University of Wisconsin - Madison

  • Merritt Losert

    University of Wisconsin - Madison

  • Trevor Knapp

    University of Wisconsin - Madison

  • Nathan Holman

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

  • Thomas McJunkin

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

  • Samuel Neyens

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

  • Evan R MacQuarrie

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

  • Ryan H Foote

    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

  • Mark G Friesen

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