基于玻色约瑟夫森结的自旋压缩的相干控制  

Coherent Control of Spin Squeezing in Boson Josephson Junctions

作　　者：杨芹英[1] 梁宝龙[1] 王继锁[1,2] 

机构地区：[1]山东省光通信科学与技术重点实验室,聊城大学物理科学与信息工程学院,山东聊城252059 [2]曲阜师范大学物理工程学院,山东曲阜273165

出　　处：《聊城大学学报（自然科学版）》2014年第1期39-42,54,共5页Journal of Liaocheng University:Natural Science Edition

基　　金：国家自然科学基金(11147009;11244005;11347026);山东省自然科学基金(ZR2012AM004;ZR2013AM012);聊城大学自然科学基金(318011308)

摘　　要：提出了利用人造原子-基于约瑟夫森结的超导量子比特产生自旋压缩的电路模型,给出了系统的有效哈密顿量.在海森堡绘景下,利用冷冻自旋近似方法得到近似解析解,进而分析了系统自旋压缩效应的调控方法.研究表明,通过调节系统粒子数或者耦合强度与有效非线性相互作用强度的比例,均可有效地调控系统的自旋压缩程度和处于自旋压缩态的时间.外场越弱,粒子数越多,系统的自旋压缩程度越强,处于自旋压缩态的时间越长.The superconducting qubit model based on the Josephson junction, whose action likes the artificial atom using for producing the spin squeezing, and its effective Hamiltonian is presented. In the Heisenberg picture, the methods to control the spin squeezing are investigated, where the approximate analytical expressions are obtained by using the frozen-spin approximation. It is demonstrated that the spin squeezing of the system can controlled availably by reasonably adjusting the total atomic number or the proportion of the coupling strength and the strength of the effective nonlinear interactions. Moreover, the extent of spin squeezing and the time scale in spin squeezing state are closely related to the strength of the external field and the atomic number.

关 键 词：玻色约瑟夫森结 自旋压缩 相干控制 冷冻自旋近似 

分 类 号：O431.2[机械工程—光学工程]