Implementing the Variational Quantum Eigensolver with native 2-qubit interaction and error mitigation

ORAL

Abstract

The variational quantum eigensolver (VQE) is an algorithm that may provide near-term applications of small-scale quantum computers, in quantum chemistry and optimisation problems. In order for the VQE to provide accurate solutions to problems on real devices, methods have been proposed recently to mitigate the errors caused by imperfect gates.
In this presentation, we report a quantum chemistry simulation using the VQE on a 2-qubit superconducting device in which we use fixed frequency qubits and build the algorithm using the native 2-qubit interaction resulting from a static capacitive coupling. The hardware ansatz of the VQE is constructed by varying the timings of echo pulses to manipulate the native ZZ coupling. This method allows us to implement a VQE algorithm without needing repeated 2-qubit-gate tune-up, and enables simple and understandable implementation of error mitigation.

*We acknowledge financial support from the EPSRC, Oxford Instruments Nanoscience, Oxford Quantum Circuits Ltd, the Oxford Centre for Applied Superconductivity, the Nakajima Foundation and the Masason Foundation.

Presenters

  • Takahiro Tsunoda

    • Condensed Matter Physics, University of Oxford

Authors

  • Takahiro Tsunoda

    • Condensed Matter Physics, University of Oxford
  • Andrew D Patterson

    • Condensed Matter Physics, University of Oxford
    • University of Oxford
  • Xiao Yuan

    • Materials, University of Oxford
  • Suguru Endo

    • Materials, University of Oxford
  • Joseph Rahamim

    • Condensed Matter Physics, University of Oxford
    • University of Oxford
  • Peter A Spring

    • Condensed Matter Physics, University of Oxford
  • Martina Esposito

    • Condensed Matter Physics, University of Oxford
    • University of Oxford
  • Salha Jebari

    • University of Oxford
    • Condensed Matter Physics, University of Oxford
  • Kitti Ratter

    • Condensed Matter Physics, University of Oxford
  • Sophia Sosnina

    • Condensed Matter Physics, University of Oxford
  • Giovanna Tancredi

    • Condensed Matter Physics, University of Oxford
  • Brian Vlastakis

    • Condensed Matter Physics, University of Oxford
  • Simon Benjamin

    • Materials, University of Oxford
  • Peter Leek

    • Condensed Matter Physics, University of Oxford
    • University of Oxford