Improved Superconducting Qubit State Readout by Path Interference  

作　　者：Zhiling Wang Zenghui Bao Yukai Wu Yan Li Cheng Ma Tianqi Cai Yipu Song Hongyi Zhang Luming Duan 王志凌;鲍增晖;吴宇恺;李严;马程;蔡天奇;宋祎璞;张宏毅;段路明(Center for Quantum Information,Institute for Interdisciplinary Information Sciences,Tsinghua University,Beijing 100084,China)

机构地区：[1]Center for Quantum Information,Institute for Interdisciplinary Information Sciences,Tsinghua University,Beijing 100084,China

出　　处：《Chinese Physics Letters》2021年第11期13-17,共5页中国物理快报（英文版）

基　　金：Supported by the Beijing Academy of Quantum Information Science;the Frontier Science Center for Quantum Information of the Ministry of Education of China through the Tsinghua University Initiative Scientific Research Program;the National Natural Science Foundation of China (Grant No. 11874235);the National Key Research and Development Program of China (Grant Nos. 2016YFA0301902 and 2020YFA0309500);support from Shuimu Tsinghua Scholar Program;the International Postdoctoral Exchange Fellowship Program。

摘　　要：High fidelity single shot qubit state readout is essential for many quantum information processing protocols. In superconducting quantum circuit, the qubit state is usually determined by detecting the dispersive frequency shift of a microwave cavity from either transmission or reflection. We demonstrate the use of constructive interference between the transmitted and reflected signal to optimize the qubit state readout, with which we find a better resolved state discrimination and an improved qubit readout fidelity. As a simple and convenient approach, our scheme can be combined with other qubit readout methods based on the discrimination of cavity photon states to further improve the qubit state readout.

关 键 词：red GAUSSIAN Improved Superconducting Qubit State Readout by Path Interference 

分 类 号：O413[理学—理论物理]