Large-bandwidth transduction between an optical single quantum-dot molecule and a superconducting resonator

  1. Yuta Tsuchimoto,
  2. Zhe Sun,
  3. Emre Togan,
  4. Stefan Fält,
  5. Werner Wegscheider,
  6. Andreas Wallraff,
  7. Klaus Ensslin,
  8. Ataç İmamoğlu,
  9. and Martin Kroner
Quantum transduction between the microwave and optical domains is an outstanding challenge for long-distance quantum networks based on superconducting qubits. For all transducers realized
to date, the generally weak light-matter coupling does not allow high transduction efficiency, large bandwidth, and low noise simultaneously. Here we show that a large electric dipole moment of an exciton in an optically active self-assembled quantum dot molecule (QDM) efficiently couples to a microwave field inside a superconducting resonator, allowing for efficient transduction between microwave and optical photons. Furthermore, every transduction event is heralded by a single-photon pulse generated at the QDM resonance, which can be used to generate entanglement between distant qubits. With an on-chip device, we demonstrate a sizeable single-photon coupling strength of 16 MHz. Thanks to the fast exciton decay rate in the QDM, the transduction bandwidth reaches several 100s of MHz.