微波驱动下超导量子比特与磁振子的相干耦合  

Coherent coupling in a driven qubit-magnon hybrid quantum system

作　　者：徐达 王逸璞 李铁夫[2] 游建强 Xu Da;Wang Yi-Pu;Li Tie-Fu;You Jian-Qiang(Department of Physics,Zhejiang University,Hangzhou 310058,China;School of Integrated Circuits,Tsinghua University,Beijing 100084,China)

机构地区：[1]浙江大学物理学系,杭州310058 [2]清华大学集成电路学院,北京100084

出　　处：《物理学报》2022年第15期10-17,共8页Acta Physica Sinica

基　　金：中国博士后科学基金(批准号:2019M660137);国家自然科学基金(批准号:11934010,12174329)资助的课题。

摘　　要：实验上展示了钇铁石榴石(YIG)晶体小球中磁振子与超导量子比特的驱动缀饰态之间的相干强耦合,磁振子的加入使得在超导量子比特中形成了双重缀饰态.实验中一个钇铁石榴石晶体小球与一个超导量子比特同时放置在三维谐振腔中,分别通过磁偶极相互作用和电偶极相互作用与谐振腔中的本征场(TE102模式)耦合,并通过腔模作为媒介实现两者之间的有效相干强耦合.给超导量子比特施加一个共振的微波驱动并改变驱动强度,测得耦合系统能级劈裂随驱动强度的变化,并理论上利用粒子-空穴对与玻色场耦合的模型做了计算.在大部分的驱动强度范围内实验结果都与理论计算结果符合得较好,表明驱动下的比特-磁振子耦合系统可以用来模拟粒子-空穴对称对与玻色场的耦合系统.本文使用的混合量子系统为模拟玻色子与费米子的混合系统提供了一个新途径.We experimentally demonstrate the strong coupling between the ferromagnetic magnons in an yttriumiron-garnet(YIG) sphere and the drive-field-induced dressed states of a superconducting qubit,which gives rise to the double dressing of the superconducting qubit.The YIG sphere and the superconducting qubit are embedded in a microwave cavity,and are coupled to the magnetic and electrical fields of the cavity TE102mode,respectively.The effective coupling between them is mediated by the virtual cavity photons of cavity TE102split of the qubit-magnon polariton occurs.These supplemental splittings indicate a double-dressed state.We theoretically analyze the experimental results by using a particle-hole symmetric model.The theoretical results fit the experimental observations well in a broad range of drive-field power parameters,revealing that the driven qubit-magnon hybrid quantum system can be used to emulate a particle-hole symmetric pair coupled to a bosonic mode.Our hybrid quantum system holds great promise for quantum simulations of composite quasiparticles consisting of fermions and bosons.

关 键 词：超导量子比特 磁振子 相干耦合 量子模拟 

分 类 号：O413[理学—理论物理] O441.2[理学—物理]