Wang Zhixin, Xu Mingrui, Han Xu, Fu Wei, Puri Shruti, Girvin S M, Tang Hong X, Shankar S, Devoret M H
Department of Applied Physics and Physics, Yale University, New Haven, Connecticut 06520, USA.
Department of Electrical Engineering, Yale University, New Haven, Connecticut 06520, USA.
Phys Rev Lett. 2021 May 7;126(18):180501. doi: 10.1103/PhysRevLett.126.180501.
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 subunit photon level. Using this radiometer, we demonstrate the radiative cooling of a 1 K microwave resonator and measure its mode temperature with an uncertainty ∼0.01 K. We thus develop a precise tool for studying the thermodynamics of quantum microwave circuits, which provides new solutions for calibrating hybrid quantum systems and detecting candidate particles for dark matter.
光子与相干量子系统的相互作用可用于以极高的灵敏度检测电磁辐射。我们介绍一种基于超导量子比特的光子诱导退相过程的量子辐射计，用于在亚单位光子水平上感测微波辐射。使用该辐射计，我们展示了1K微波谐振器的辐射冷却，并以约0.01K的不确定度测量其模式温度。因此，我们开发了一种用于研究量子微波电路热力学的精确工具，为校准混合量子系统和检测暗物质候选粒子提供了新的解决方案。
