Observation of dark states in a superconductor diamond quantum hybrid system

ORAL

Abstract

We observed a remarkably sharp resonance ($\sim$ 1 MHz) at 2.878 GHz in the spectrum of flux qubit NV-diamond hybrid quantum system under zero external magnetic field. This width is much narrower than that of both the flux-qubit and spin-ensemble. We show this resonance is evidence of a collective dark state in the ensemble which is coherently driven by the superposition of clockwise and counter-clockwise macroscopic persistent super-currents owing in the flux qubit.

Authors

  • Xiaobo Zhu

    • NTT Basic Research Laboratories
  • Yuichiro Matsuzaki

    • NTT Basic Research Laboratories
  • Robert Amsuss

    • Vienna Center for Quantum Science and Technology
  • Kosuke Kakuyanagi

    • NTT Basic Research Laboratories
  • Takaaki Shimo-Oka

    • Graduate School of Engineering Science, Osaka University
  • Norikazu Mizuochi

    • Graduate School of Engineering Science, Osaka University
  • Kae Nemoto

    • National Institute of Informatics
  • William J. Munro

    • NTT Basic Research Laboratories
  • Kouichi Semba

    • National Institute of Informatics
  • Shiro Saito

    • NTT Basic Research Laboratories