基于局域耦合相位调控的巨原子单光子散射  

Single-photon Scattering in Giant-atom Waveguide Systems with Modulated Coupling Phases

作　　者：李姝瑜 吴怀志[1] 韩亚帅 胡长生 LI Shu-yu;WU Huai-zhi;HAN Ya-shuai;HU Chang-sheng(Fujian Key Laboratory of Quantum Information and Quantum Optics&Department of Physics,Fuzhou University,Fuzhou 350116,China;School of Physics and Electronic Information,Anhui Normal University,Wuhu 241002,China)

机构地区：[1]福州大学福建省量子信息与量子光学重点实验室&物理系,福建福州350116 [2]安徽师范大学物理与电子信息学院,安徽芜湖241002

出　　处：《量子光学学报》2024年第2期18-29,共12页Journal of Quantum Optics

基　　金：国家自然科学基金(11774058,12174058)。

摘　　要：人造巨原子与波导多点耦合系统可打破传统量子光学偶极近似,诱导原子自干涉效应,近年来成为研究光子散射的重要物理平台。本文研究了该模型与一维波导多点手性耦合时,耦合点局域相位对单光子散射的影响。通过实空间哈密顿量方法精准解得系统的透射率与反射率表达式,传播相位被修正为依赖于入射光传播方向的手性相位,并通过设计手性相位来研究散射谱中手性引起的效应。研究发现当手性相位满足与耦合点个数无关的条件时,可使得兰姆能移消失,入射光子的透射谱能在共振处实现完美透射到完全反射的转变。此外,本文展现了引入原子内部自发辐射后,无需利用非马尔可夫延迟效应,仅调控手性相位即可实现完美的非互易光子散射。本文研究表明具有手性耦合点局域相位的巨原子-波导系统能为实现单光子路由提供颇具前景的候选平台。Objective In quantum optics,(nature)atoms are orders of magnitude smaller than the wavelength of the light they interact with,which justifies the dipole approximation by allowing them to be viewed as point-like emitters.However,recent experiments extending the small(nature)atom platform to artificial'giant'atomic systems built from superconducting circuits,represent a breakdown of the dipole approximation and have attracted significant attention.The waveguide quantum electrodynamics systems with giant atoms have emerged as a new promising platform for engineering transport of photons and single-photon routing.The system enables strong tunable atom-waveguide coupling and manifests multiple-point self-interference in the photon scattering spectra.Recently,a setup with chiral interfaces between giant atoms and waveguides is no longer challenging based on technological progress,in particular,the chiral coupling can also allow decoherence-free states,nonreciprocal photon transport,and tunable Markovianity.Few studies have also considered the unequal local phases at different coupling points for photon routing.Nevertheless,here we study the single-photon scattering problem by considering chiral local coupling phases.Method We consider the system Hamiltonian in real-space and linear dispersion relation.We solve the Schrödinger equation within the single-photon manifold by considering theδ-function potential effect of the atom at the coupling point,where an appropriate ansatz is used for the probability amplitudes of the system's state,and the transmission and reflection coefficients are found with the direction-dependent propagating phases.The effects induced by chiral phases in the scattering spectra are studied by engineering the local coupling phases and coupling strengths.Results and Discussions We show that the transmission spectrum of an incident photon can transition from complete transmission to total reflection when the chiral phases satisfy specific conditions,regardless of the number of coupling points.In p

关 键 词：巨原子 波导量子电动力学 原子自干涉效应 单光子散射 手性耦合 

分 类 号：O431.2[机械工程—光学工程]