Automated In Situ Optimization and Disorder Mitigation in a Quantum Device

arXiv (Cornell University)

Abstract

We investigate automated in situ optimization of the potential landscape in a quantum point contact device, using a $3 \times 3$ gate array patterned atop the constriction. Optimization is performed using the covariance matrix adaptation evolutionary strategy, for which we introduce a metric for how "step-like" the conductance is as the channel becomes constricted. We first perform the optimization of the gate voltages in a tight-binding simulation and show how such in situ tuning can be used to mitigate a random disorder potential. The optimization is then performed in a physical device in experiment, where we also observe a marked improvement in the quantization of the conductance resulting from the optimization procedure.

Authors 12

1. Jacob Benestad

   Norwegian University of Science and Technology

   Affiliation as printed

   Center for Quantum Spintronics , Department of Physics , Norwegian University of Science and Technology , NO-7491 Trondheim , Norway

2. Torbjørn Rasmussen
3. Bertram Brovang
4. Oswin Krause
5. Saeed Fallahi
6. Geoffrey C. Gardner
7. Michael J. Manfra
8. Charles M. Marcus
   Affiliation as printed

   Center for Quantum Devices , Niels Bohr Institute ,

9. Jeroen Danon

   Norwegian University of Science and Technology

   Affiliation as printed

   Center for Quantum Spintronics , Department of Physics , Norwegian University of Science and Technology , NO-7491 Trondheim , Norway

10. Ferdinand Kuemmeth
11. Anasua Chatterjee
12. Evert van Nieuwenburg Aachen Lorentz Institute and Leiden Institute of Advanced Computer Science

    Leiden University · University of Regensburg

    Affiliation as printed

    Institute of Experimental and Applied Physics , University of Regensburg , 93040 Regensburg , Germany

    Lorentz Institute and Leiden Institute of Advanced Computer Science , Leiden University , P.O. Box 9506 , 2300 RA Leiden , The Netherlands