Characterizing noise correlation and enhancing coherence via qubit motion  

作　　者：Jiaxiu Han Zhiyuan Li Jingning Zhang Huikai Xu Kehuan Linghu Yongchao Li Chengyao Li Mo Chen Zhen Yang Junhua Wang Teng Ma Guangming Xue Yirong Jin Haifeng Yu 

机构地区：[1]Beijing Academy of Quantum Information Sciences,Beijing 100193,China

出　　处：《Fundamental Research》2021年第1期10-15,共6页自然科学基础研究（英文版）

基　　金：This work was supported by the NSFC of China(Grants nos.11890704,12004042,11674376,11905100);the NSF of Beijing(Grant no.Z190012);National Key Research and Development Pro-gram of China(Grants no.2016YFA0301800);the Key-Area Re-search and Development Program of GuangDong Province(Grants no.2018B030326001).

摘　　要：The identification of spacial noise correlation is of critical importance in developing error-corrected quantum devices,but it has barely been studied so far.In this work,we utilize an effective method called qubit motion,to efficiently determine the noise correlations between any pair of qubits in a 7-qubit superconducting quantum system.The noise correlations between the same pairs of qubits are also investigated when the qubits are at distinct operating frequencies.What’s more,in this multi-qubit system with the presence of noise correlations,we demonstrate the enhancing effect of qubit motion on the coherence of logic qubits,and we propose a Motion-CPMG operation sequence to more efficiently protect the logic state from decoherence,which is experimentally demonstrated to extend the coherence time of logic qubits by nearly one order of magnitude.

关 键 词：Qubit motion Noise correlation DECOHERENCE CPMG Quantum error correction 

分 类 号：O413[理学—理论物理]