Landau–Zener–Stückelberg Interference in Nonlinear Regime  

作　　者：Tong Wu Yuxuan Zhou Yuan Xu Song Liu Jian Li 吴桐;周宇轩;徐源;刘松;李剑(Department of Physics Harbin Institute of Technology;Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and Technology;Shenzhen Key Laboratory of Quantum Science and Engineering Southern University of Science and Technology;Center for Quantum Computing Peng Cheng Laboratory)

机构地区：[1]Department of Physics,Harbin Institute of Technology,Harbin 150001 [2]Institute for Quantum Science and Engineering and Department of Physics,Southern University of Science and Technology,Shenzhen 518055 [3]Shenzhen Key Laboratory of Quantum Science and Engineering,Southern University of Science and Technology,Shenzhen 518055 [4]Center for Quantum Computing,Peng Cheng Laboratory,Shenzhen 518055

出　　处：《Chinese Physics Letters》2019年第12期36-39,共4页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant No 11874065;the Key R&D Program of Guangdong Province under Grant No 2018B030326001;the Guangdong Innovative and Entrepreneurial Research Team Program under Grant No 2016ZT06D348;the Natural Science Foundation of Guangdong Province under Grant No 2017B030308003;the Natural Science Foundation of Hunan Province under Grant No 2018JJ1031;the Science,Technology and Innovation Commission of Shenzhen Municipality under Grant Nos ZDSYS20170303165926217,JCYJ20170412152620376 and KYTDPT20181011104202253

摘　　要：Landau-Zener-Stückelberg(LZS)interference has drawn renewed attention to quantum information processing research because it is not only an effective tool for characterizing two-level quantum systems but also a powerful approach to manipulate quantum states.Superconducting quantum circuits,due to their versatile tunability and degrees of control,are ideal platforms for studying LZS interference phenomena.We use a superconducting Xmon qubit to study LZS interference by parametrically modulating the qubit transition frequency nonlinearly.For dc flux biasing of the qubit slightly far away from the optimal flux point,the qubit excited state population shows an interference pattern that is very similar to the standard LZS interference in linear regime,except that all bands shift towards lower frequencies when increasing the rf modulation amplitude.For dc flux biasing close to the optimal flux point,the negative sidebands and the positive sidebands behave differently,resulting in an asymmetric interference pattern.The experimental results are also in good agreement with our analytical and numerical simulations.Landau–Zener–Stückelberg(LZS) interference has drawn renewed attention to quantum information processing research because it is not only an effective tool for characterizing two-level quantum systems but also a powerful approach to manipulate quantum states. Superconducting quantum circuits, due to their versatile tunability and degrees of control, are ideal platforms for studying LZS interference phenomena. We use a superconducting Xmon qubit to study LZS interference by parametrically modulating the qubit transition frequency nonlinearly.For dc flux biasing of the qubit slightly far away from the optimal flux point, the qubit excited state population shows an interference pattern that is very similar to the standard LZS interference in linear regime, except that all bands shift towards lower frequencies when increasing the rf modulation amplitude. For dc flux biasing close to the optimal flux point, the negative sidebands and the positive sidebands behave differently, resulting in an asymmetric interference pattern. The experimental results are also in good agreement with our analytical and numerical simulations.

关 键 词：BANDS QUANTUM LANDAU 

分 类 号：O41[理学—理论物理]