规范势下正方形格点超导量子比特电路中的量子态输运  

Quantum state transport in a square-lattice superconducting qubit circuit under gauge potential

作　　者：赵艳军 谭宁 王堉琪 郑亚锐 王辉 刘伍明[4,5] Zhao Yan-Jun;Tan Ning;Wang Yu-Qi;Zheng Ya-Rui;Wang Hui;Liu Wu-Ming(Key Laboratory of Opto-electronic Technology,Ministry of Education,Beijing University of Technology,Beijing 100124,China;Quantum Technology(Shenzhen)Co.,Ltd.,Shenzhen 518033,China;Inspur Artificial Intelligence Research Institute,Jinan 250011,China;Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;College of Physics,University of Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]北京工业大学,光电子技术教育部重点实验室,北京100124 [2]量元科技(深圳)有限公司,深圳518033 [3]浪潮人工智能研究院,济南250011 [4]中国科学院物理研究所,北京凝聚态物理国家实验室,北京100190 [5]中国科学院大学物理学院,北京100190

出　　处：《物理学报》2023年第10期74-85,共12页Acta Physica Sinica

基　　金：北京市自然科学基金(批准号:4222064);国家自然科学基金(批准号:11904013,61835013,12234012);国家重点研发计划(批准号:2021YFA1400900,2021YFA0718300,2021YFA1402100);中国载人航天工程空间应用系统项目资助的课题.

摘　　要：借助于电感型耦合器产生人造规范势(有效磁通),本文研究了正方形传输子量子比特模型中的量子态输运性质.理论计算发现,单粒子本征态与单空穴本征态具有相同的本征能谱,并且相同能量下,两者的平均粒子流与平均空穴流受有效磁通正弦调制后互为相反数.当初态为占据一个格点的单粒子与单空穴时,如果系统时间反演对称(有效磁通为4π的整数倍),单粒子与单空穴的含时波函数各分量相等,否则不等.分析证明,以上计算结果是由于对体系哈密顿量的粒子-空穴操作等价于对其做时间反演.此外还发现,有效磁通为π时,单粒子或单空穴只在初始比特与两个相邻比特之间输运,有效磁通为0时,单粒子或单空穴通过两个相邻比特输运到对角比特,然后再反向输运;无论有效磁通如何取值,两者具有相同的平均(粒子或空穴)流和格点占据概率.In this paper,we study the transport properties of quantum states in the square-lattice quantum bit model by using inductive couplers to generate the artificial gauge potential(effective magnetic flux).It is found by theoretical calculation that the eigenstates of single particle and single hole have the same eigen energy spectrum,and the average particle and hole currents,sinusoidally modulated by the effective magnetic flux,are opposite to each other with respect to the same eigen energy.For an initial single-particle or single-hole state where only one lattice site is occuplied,if the time-inversion symmetry is preserved(the effective magnetic flux is an integral multiple of 4π),the components of the time-dependent wave functions of the single particle and the single hole are equal,otherwise they are not equal.The analysis demonstrates that the above calculation results are due to the fact that the particle-hole operation for the system Hamiltonian is equivalent to the time inversion.In addition,it is found that when the effective magnetic flux isπ,a single particle or a single hole is only transported between the initial bit and two adjacent bits,and when the effective magnetic flux is 0,a single particle or a single hole is transported to the diagonal bit through two adjacent bits,and then transported in reverse.Regardless of the value of effective magnetic flux,both the single-particle and single-hole states share the same average(particle or hole)current and lattice site occupation probability.

关 键 词：规范势 量子态输运 量子态制备 

分 类 号：O413[理学—理论物理]