等效零折射率材料微腔中均匀化腔场作用下的简正模劈裂现象  

Normal-mode splitting induced by homogeneous electromagnetic fields in cavities filled with effective zero-index metamaterials

作　　者：徐小虎 陈永强 郭志伟[3] 孙勇[3] 苗向阳[1] 

机构地区：[1]山西师范大学物理与信息工程学院,临汾041004 [2]苏州科技大学物理科学与技术学院,江苏省微纳热流技术与能源应用重点实验室,苏州215009 [3]同济大学物理科学与工程学院,教育部先进微结构材料重点实验室,上海200092

出　　处：《物理学报》2018年第2期161-166,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号：11404204,51607119,11674247)资助的课题

摘　　要：研究了零折射率材料微腔中人造原子与腔模的相干耦合现象.首先通过数值模拟的方法研究了在二维光子晶体微腔中填充阻抗匹配的零折射率材料后腔模的场分布.结果表明零折射率材料的引入使得原本以驻波场形式存在的腔模分布在整个微腔中变得近似均匀且值最大.其次,将人造原子放入腔中的不同位置并与腔模耦合,结果从频谱上观察到腔模的劈裂与人造原子在腔中的位置无关.最后,利用微波实验,通过开口谐振环等效的人造原子与一维复合左右手传输线等效的零折射率材料微腔之间的耦合验证了仿真结果的准确性.该结果为腔量子电动力学中量子点对位难的问题提供了新的方案,同时零折射率材料微腔也为今后研究原子与光子之间的相互作用提供了一个新的平台.In cavity quantum electrodynamics（cQED）, how an atom behaves in a cavity is what people care about. The coupling strength（g） between cavity field and atoms plays a fundamental role in various QED effects including Rabi splitting. In the solid-state case, when an atomic-like two-level system such as a single quantum dot（QD） is placed into a cavity, Rabi splitting would occur if g is strong enough. In the classical limit, when a QD in a cavity changes into a classical oscillator, the normal-mode splitting would also take place. It is known that g relies on the local fields at the places of the QDs or classical oscillators inside the cavity. However, for both cases, the traditional cavity modes involved are all in the form of standing waves and the localized fields are position-dependent. To ensure strong coupling between QDs or classical oscillators and photons, they should be placed right at the place where the cavity field is maximum,which is very challenging. How is the positional uncertainty overcome？Recently, the peculiar behaviors of electromagnetic（EM） fields inside zero-index metamaterial（ZIM） in which permittivity ε and/or permeability μ are zero have aroused considerable interest. In ZIMs the propagating phase everywhere is the same and the effective wavelength is infinite, which strongly changes the scattering and mode properties of the EM waves. In addition to the above characteristics, the fields in ZIM could be homogeneous as required by Maxwell equations. While the special properties of ZIMs are investigated, the fabrication of ZIMs is widely studied. It is found that a two dimensional（2 D） photonic crystal consisting of a square lattice of dielectric rods with accidental degeneracy can behave as a loss-free ZIM at Dirac point.To overcome the positional uncertainty, in this paper we propose a cavity filled with effective zero-index metamaterial（ZIM）. When the ZIM is embedded in a cavity, the enhanced homogeneous fields can occur under the resonance condition.Finally, e

关 键 词：光子晶体 特异材料 腔量子电动力学 

分 类 号：TB303[一般工业技术—材料科学与工程]