Quantum bath suppression in a superconducting circuit by immersion cooling
Journal article, 2023
Quantum circuits interact with the environment via several temperature-dependent degrees of freedom. Multiple experiments to-date have shown that most properties of superconducting devices appear to plateau out at T ≈ 50 mK – far above the refrigerator base temperature. This is for example reflected in the thermal state population of qubits, in excess numbers of quasiparticles, and polarisation of surface spins – factors contributing to reduced coherence. We demonstrate how to remove this thermal constraint by operating a circuit immersed in liquid 3He. This allows to efficiently cool the decohering environment of a superconducting resonator, and we see a continuous change in measured physical quantities down to previously unexplored sub-mK temperatures. The 3He acts as a heat sink which increases the energy relaxation rate of the quantum bath coupled to the circuit a thousand times, yet the suppressed bath does not introduce additional circuit losses or noise. Such quantum bath suppression can reduce decoherence in quantum circuits and opens a route for both thermal and coherence management in quantum processors.
Author
M. Lucas
Royal Holloway University of London
Andrey Danilov
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
L. V. Levitin
Royal Holloway University of London
Aditya Jayaraman
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
A. J. Casey
Royal Holloway University of London
L. Faoro
Google Inc.
Alexander Tzalenchuk
Royal Holloway University of London
National Physical Laboratory (NPL)
Sergey Kubatkin
Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics
J. Saunders
Royal Holloway University of London
Sebastian Erik de Graaf
National Physical Laboratory (NPL)
Nature Communications
2041-1723 (ISSN) 20411723 (eISSN)
Vol. 14 1 3522European Microkelvin Platform (EMP)
European Commission (EC) (EC/H2020/824109), 2019-01-01 -- 2022-12-31.
Mikrovågsförstärkare med kvantbegränsad prestanda
Swedish Research Council (VR) (2016-04828), 2017-01-01 -- 2020-12-31.
Ultima gränsen för känsliga komponenter: Supraledande kvantkrets i form av resonator vid ultralåg temperatur
Swedish Research Council (VR) (2019-05480), 2020-01-01 -- 2023-12-31.
Wallenberg Centre for Quantum Technology (WACQT)
Knut and Alice Wallenberg Foundation (KAW 2017.0449, KAW2021.0009, KAW2022.0006), 2018-01-01 -- 2030-03-31.
Quantum noise pathfinder
Swedish Research Council (VR) (2020-04393), 2021-01-01 -- 2024-12-31.
Subject Categories (SSIF 2011)
Atom and Molecular Physics and Optics
Theoretical Chemistry
Condensed Matter Physics
DOI
10.1038/s41467-023-39249-z
PubMed
37316500
Related datasets
Dataset for "Quantum bath suppression in a superconducting circuit by immersion cooling" [dataset]
DOI: 10.5281/zenodo.7937066