Automated In Situ Optimization and Disorder Mitigation in a Quantum Device

Physical Review Letters, vol. 135, pp. 216301

Abstract

We investigate automated in situ optimization of the potential landscape in a quantum point contact device, using a 3×3 gate array patterned atop the constriction. Optimization is performed using the covariance matrix adaptation evolutionary strategy, for which we introduce a metric for how "steplike" 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

   Norwegian University of Science and Technology

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

2. Torbjørn Rasmussen

   University of Copenhagen · QuTech · Delft University of Technology

   Affiliation as printed

   Delft University of Technology

   University of Copenhagen

   Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark

   QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands

3. Bertram Brovang

   University of Copenhagen

   Affiliation as printed

   University of Copenhagen

   Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark

4. Oswin Krause

   University of Copenhagen

   Affiliation as printed

   University of Copenhagen

   Department of Computer Science, University of Copenhagen, 2100 Copenhagen, Denmark

5. Saeed Fallahi

   Purdue University West Lafayette

   Affiliation as printed

   Purdue University

   Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA

6. Geoffrey C. Gardner

   Purdue University West Lafayette

   Affiliation as printed

   Purdue University

   Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA

7. Michael J. Manfra

   Purdue University West Lafayette

   Affiliation as printed

   Purdue University

   School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907, USA

8. Charles M. Marcus

   University of Copenhagen

   Affiliation as printed

   University of Copenhagen

   Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark

9. Jeroen Danon

   Norwegian University of Science and Technology

   Affiliation as printed

   Norwegian University of Science and Technology

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

10. Ferdinand Kuemmeth

    University of Copenhagen · University of Regensburg

    Affiliation as printed

    University of Copenhagen

    University of Regensburg

    Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark

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

11. Anasua Chatterjee

    University of Copenhagen · QuTech · Delft University of Technology

    Affiliation as printed

    Delft University of Technology

    University of Copenhagen

    Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark

    QuTech and Kavli Institute of Nanoscience, Delft University of Technology, 2600 GA Delft, The Netherlands

12. Evert van Nieuwenburg Aachen

    Leiden University

    Affiliation as printed

    Leiden University