A programmable two-qubit quantum processor in silicon

 · Invited

Abstract

Building small-scale quantum computers where initialisation, readout, single and two-qubit gates are combined to perform computation result in new challenges such as qubit cross talk, state leakage, and calibration. Here, we overcome these challenges to demonstrate a programmable two-qubit quantum processor using single electron spins in silicon [1]. In the natural Si/SiGe double quantum dot device, single qubit gates (2 MHz) with fidelities > 98% are achieved using electric dipole spin resonance [2] while a two-qubit gate (5-20 MHz) is realised using the exchange coupling between the two electron spins [3]. We characterise entanglement in our processor by performing quantum state tomography on Bell states where we achieve state fidelities between 85-90% and concurrences between 73-80%. Finally, we demonstrate the programmability of the processor by successfully running both the Deutsch-Jozsa and the Grover search algorithms.
[1] T. F. Watson et al., arxiv: 1708.04214 (2017)
[2] E. Kawakami et al., Nature Nanotechnology 9, 666 (2014)
[3] M. Veldhorst et al., Nature 526, 410 (2015)

*Research was sponsored by the Army Research Office (ARO), and was accomplished under Grant Numbers W911NF-17-1-0274 and W911NF-12-1-0607. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or

Presenters

  • Thomas Watson

    • Delft University of Technology
    • CQC2T, Univ of New South Wales

Authors

  • Thomas Watson

    • Delft University of Technology
    • CQC2T, Univ of New South Wales
  • Stephan Phillips

    • Delft University of Technology
  • Erika Kawakami

    • Delft University of Technology
  • Daniel Ward

    • Sandia National Labs
    • Sandia National Laboratories
    • University of Wisconsin-Madison
    • Center for Computing Research, Sandia National Labs
  • Pasquale Scarlino

    • ETH - Zurich
    • Delft University of Technology
    • Physics, ETH Zurich
    • Department of Physics, ETH Zurich
  • Menno Veldhorst

    • Delft Univ of Tech
    • Delft University of Technology
    • QuTech and Kavli Institute of Nanoscience, TU Delft
  • D. E. Savage

    • University of Wisconsin-Madison
    • Materials Science and Engineering, University of Wisconsin: Madison
  • Max Lagally

    • University of Wisconsin-Madison
    • Materials Science and Engineering, University of Wisconsin: Madison
    • Materials Science and Engineering, Univ of Wisconsin-Madison
  • Mark Friesen

    • Physics, University of Wisconsin-Madison
    • Univ of Wisconsin, Madison
    • University of Wisconsin-Madison
    • Department of Physics, Univ of Wisconsin, Madison
    • Department of Physics, University of Wisconsin - Madison
    • Department of Physics, University of Wisconsin-Madison
    • Physics, Univ of Wisconsin, Madison
  • Susan Coppersmith

    • Physics, University of Wisconsin-Madison
    • Univ of Wisconsin, Madison
    • University of Wisconsin-Madison
    • Physics, University of Wisconsin: Madison
    • Department of Physics, Univ of Wisconsin, Madison
    • Department of Physics, University of Wisconsin - Madison
    • Department of Physics, University of Wisconsin-Madison
    • Physics, Univ of Wisconsin, Madison
  • M. A. Eriksson

    • Physics, University of Wisconsin-Madison
    • University of Wisconsin-Madison
    • Physics, University of Wisconsin: Madison
    • Univ of Wisconsin, Madison
    • Department of Physics, University of Wisconsin-Madison
  • Lieven Vandersypen

    • Delft University of Technology
    • QuTech and Kavli Institute of Nanoscience, TU Delft
    • QuTech & Kavli Institute of Nanoscience, TU Delft
    • QuTech, Delft University of Technology
    • QuTech and Kavli Institute of NanoScience, Delft University of Technology
    • TU Delft