兰州大学机构库 >物理科学与技术学院
失谐对耗散耦合腔阵列中超流-绝缘相变的影响
Alternative TitleThe Influences of Detuning on the Superfluid-Insulator Phase Transition In Coupled Dissipative Cavity Arrays
鲍佳
Thesis Advisor谭磊
2013-05-31
Degree Grantor兰州大学
Place of Conferral兰州
Degree Name硕士
Keyword耦合腔阵列 极化激元 耗散 失谐 量子相变
Abstract近年来,实验技术在冷原子操控、制备高品质光学微腔、编织大尺度微腔阵列以及实现腔场与原子强耦合等方面取得的进展,使耦合腔阵列成为一种可能的实验工具,人们期待它能像光晶格那样有助于于量子信息处理、量子计算和量子模拟器的实现。在量子光学中,耦合腔阵列已被用作实验平台来模拟强关联多体物理。Jaynes-Cummings-Hubbard模型描述的耦合Quantum Electrodynamics(QED)腔阵列系统中极化激元的超流-绝缘相变就是一个典型的例子。 然而,像其它所有量子光学系统一样,实际存在的耦合腔阵列系统并非理想系统,因其不可避免地与环境发生耦合,且这种耦合会导致系统发生退相干、退相位等。此外,失谐的存在也会对系统的性质产生重大影响,因此有必要搞清楚这些因素影响系统性质的物理机制。 本文借用一种有效剔除环境(库场)自由度的准玻色子方法,得到Jaynes-Cummings-Hubbard模型的有效哈密顿量,并结合单格点平均场理论和微扰论得到了失谐情况下系统的超流序参量。在此基础上,讨论了失谐对系统超流-绝缘相变的影响。通过研究我们发现调节失谐可以改变腔间的有效排斥势,使系统极化激元在超流和绝缘态之间实现转变。此外,我们还结合失谐情况下耗散耦合腔阵列的输运性质定性讨论了失谐对系统中超流序参量和超流的时间的影响。研究结果表明:沿失谐负支随着失谐的增大,序参量会经历先增后减的过程,这与系统的透射谱有些相似。
Other AbstractRecently, the progresses of experimental techniques in trapping and cooling atoms, constructing high-quality optical microcavity, fabricating large-scale arrays of coupled cavities and engineering strong interaction of atoms and photons make coupled cavity arrays to be petential instruments, which are expected to contribute to the realization of the processing of quantum information, the inplementation of quantum computation and the quantum simulators as optical lattices does. In quantum opeics, coupled cavity arrays are used as quantum simulators of many-body physics in strongly correlated systems. A prominent example is the superfloid-insulator phase transition of polaritons in coupled QED cavity arrays as described by the Jaynes-Cummings-Hubbard model. However, in practical, as all the others quantum optical systems, experimental coupled cavity arrays are inevitably coupled to the reservior and so exposed to the dissipation, which will accumulate with time until the system break down(decoherence). In addition, the detuming will also affect the dynamics of the system, so it is necessary to figure out how this factors will affact the behaviors of the system thronghout its lifetime. In this paper, we employ a kind of quasi-bosons approah to remove the degrees of fredom of the enviroment (reservoir), carry out the effective Jaynes-Cummings-Hubbard model Hamiltonian in the presence of detuning. Then, cmbining with the single-site mean-field and perturbation theory, we figure out the superfluid order parameter of the system. By which we find that detuning from resonance allows to drive the system from the superfluid into the insulator state of the polaritons and the reverse. In addition, combining with the properties of transportation of coupled dissipative cavity arrays with detuning, we discuss the influence of detuning on the number of superfluid polaritons and the lifetime of superfuiid states. Ir suggests that the number of the superfluid polaritons will increaxe to its maximum and then reduce again along the negative part of detuning, which is similar to the spectrum of the tuansmission.
URL查看原文
Language中文
Document Type学位论文
Identifierhttps://ir.lzu.edu.cn/handle/262010/229389
Collection物理科学与技术学院
Recommended Citation
GB/T 7714
鲍佳. 失谐对耗散耦合腔阵列中超流-绝缘相变的影响[D]. 兰州. 兰州大学,2013.
Files in This Item:
There are no files associated with this item.
Related Services
Recommend this item
Bookmark
Usage statistics
Export to Endnote
Altmetrics Score
Google Scholar
Similar articles in Google Scholar
[鲍佳]'s Articles
Baidu academic
Similar articles in Baidu academic
[鲍佳]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[鲍佳]'s Articles
Terms of Use
No data!
Social Bookmark/Share
No comment.
Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.