Wang, Zhixin

Date:   Tuesday, July 30, 2019
Time:   11:00
Place:   ETH Zurich, Hönggerberg, HPF G 6
Host:    Andreas Wallraff

Quantum Microwave Radiometry with a
Superconducting Qubit

Zhixin Wang
Yale University, New Haven, Connecticut, USA

The interaction of photons and coherent quantum systems can be employed to detect electromagnetic radiation with remarkable sensitivity. We introduce a quantum radiometer based on the photon-induced-dephasing process of a superconducting qubit for sensing microwave radiation at the sub-unit-photon level. Using this radiometer, we demonstrated the radiative cooling of a 1-K microwave resonator and measured its mode temperature with uncertainty ~0.01 K. We have thus developed a precise tool for studying the thermodynamics of quantum microwave circuits, which provides new solutions for calibrating hybrid quantum systems and tracing candidate particles for dark matter.