Superconducting Quantum Circuits

Superconducting qubits are recognised to be a leading candidate for quantum computing and sensor applications. Understanding decoherence in superconducting qubits is a major current challenge. Our strategy is to use effective cooling of quantum circuits by a quantum fluid bath for thermal and coherence management.

 

This strategy is based on our study of superconducting resonators, which demonstrated not only cooling (to 1 mK) but also very significant noise mitigation [1]. In this case the dominant source of noise was two level systems.

Superconducting Quantum Circuits

Our current programme involves:

 

  • Study of performance of qubits immersed in a quantum fluid bath to unravel decoherence budget.
  • Evaluation of different quantum fluid baths: 3He (pressure/normal/superfluid), 3He -4He mixtures, eliminate (nuclear) magnetic solid 3He surface boundary layer.
  • Theory of quantum bath-quantum circuit interaction, with partners.
  • Feasibility of quantum fluid immersion based quantum computer.

This project is in close collaboration with National Physical Laboratory, Chalmers University, Glasgow University, Karlsruhe Institute of Technology, Louisiana State University, Google Quantum AI, Oxford Instruments,  and the Fermilab Quantum Center, SQMS.

References

 

  1. Quantum bath suppression in a superconducting quantum circuit by immersion cooling. M. Lucas, A.V. Danilov, L.V. Levitin, A. Jayaraman, A. J. Casey, L. Faoro, A. Ya. Tzalenchuk, S. E. Kubatkin, J. Saunders and S. E. de Graaf, Nature Communications, 14, 3522 (2023) https://doi.org/10.1038/s41467-023-39249-z