Superconducting Qubit based Quantum Heat Switch

Alberto Ronzani¹, Bayan Karimi¹, Jorden Senior¹, Yu-Cheng Chang^2,3, Joonas T. Peltonen¹, ChiiDong Chen^3*, Jukka P. Pekola¹

¹Department of Applied Physics, Aalto University School of Science, Aalto, Finland
²Department of Physics, National Taiwan University, Taipei, Taiwan
³Institute of Physics, Academia Sinica, Taipei, Taiwan

* Presenter:ChiiDong Chen, email:chiidong@phys.sinica.edu.tw

We reported a quantum switch that can control the heat transport between two nominally identical incoherent heat reservoirs. The heat switch is a X-mon qubit whose level spacing is tunable by an externally applied magnetic field. Each heat reservoir consists of a quarter-wavelength coplanar waveguide resonator which is capacitively coupled to the qubit at one end and terminated to the ground via a copper strip at the other end. The copper strip is DC connected to two aluminum electrodes through aluminum oxide tunnel barriers, forming a superconductor-insulator-normal metal-insulator-superconductor (SINIS) tunneling device. The SINIS devices plays the roles of heater in one reservoir and thermometer in the other reservoir. We observed tunable photonic heat transport through this reservoir-qubit-reservoir circuit and noted that the interplay between the qubit-resonator coupling and the resonator-SINIS coupling can lead to qualitatively dissimilar switching behaviors.

Keywords: superconducting qubit, quantum heat switch, coplanar waveguide resonator, SINIS tunneling device, photon-atom coupling