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)

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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