利用回音壁微腔系统克服量子点能级自然分裂  

Whispering-gallery-cavity-assisted overcoming the fine structure splitting of the quantum dot

作　　者：柏江湘[1] 李德俊[1] 米贤武[1] 

机构地区：[1]吉首大学物理科学与信息工程学院,吉首416000

出　　处：《中国科学：物理学、力学、天文学》2011年第7期824-831,共8页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(批准号:10647132);湖南省教育厅科学(编号:09C825;10A100)资助项目

摘　　要：用一种全量子理论方法研究了一回音壁微腔-V型三能级量子点系统之间的耦合.量子点分别由基态、左圆极化激子态和右圆极化激子态构成,两简并回音壁腔模分别与左激子跃迁模和右激子跃迁模相耦合,其耦合率分别为gL和gR.在实空间里,我们推导了透射模与反射模的精确解,并得出其数值结果.结果显示了复合系统的耦合动力学特性;更重要的是,我们可以通过设计微腔得到合适的微腔反向散射率?,利用双模与量子点强耦合,就可以克服双激子能级精细结构的分裂(FSS).A composite system is investigated by a full quantum approach, two orthogonal degenerate whispering-gallery cavity modes coupling to a quantum dot （QD）. The energy levels of the QD are modeled by a three-level system consisting of the ground state, right- and left-polarized excitons. The counterclockwise mode and the clockwise mode are coupled with the transitions with respect to right- and left-polarized excitons, respectively. We analyze the photon transport of the composite system, describing the coupling between the QD and the two cavity modes by two parameters gR and gL. The transmission and reflection amplitudes are solved exactly via a real-space approach. The numerical results of the system show mixed nature both of the cavity and the QD, and one can overcome the excitons fine structure splitting （FSS） via getting a appropriate backscattering rate β by fine designing the cavity.

关 键 词：回音壁微腔 双激子量子点 模耦合 精细结构分裂 

分 类 号：O431.2[机械工程—光学工程] O471.1[理学—光学]