旋转二维激子极化激元凝聚涡旋叠加态的动力学特性

Rotational dynamics characteristics of planar superimposed vortices of exciton polariton condensates

研究了二维激子极化激元凝聚正反涡旋叠加态在半导体微腔极化激元波色爱因斯坦凝聚(Bose-Einstein condensate,BEC)体系旋转情形下的稳定性和动力学特性.在体系旋转情形下对单分量Gross-Pitaevskii方程进行重构,利用四阶龙格库塔方法和时域有限差分方法构建数值模型.利用实时演化方法研究在体系旋转的情况下,不同拓扑荷数的正反涡旋叠加态的实时演化过程及稳态局域粒子数和体系旋转角速率之间的关系.研究了涡旋叠加态激发区域的旋转速率与体系旋转速率的关系,并阐明了体系的旋转速率对涡旋叠加态相位稳定性的影响机理.研究表明,半导体微腔极化激元BEC体系的旋转速率对激子极化激元凝聚叠加态的演化过程及其动力学特性有重要影响.

The gyroscope established on quantization vortices formed from exciton-polariton Bose-Einstein condensate has important potential applications in the field of quantum guidance.Thus,we assume a concept of quantum gyroscope based on Sagnac effect of the superposition states of quantum vortices existing in exciton-polariton condensates.To study the gyroscopic effect of superimposed vortices,which is the core issue of the project,it is essential to study the dynamic characteristics in the case of system rotating.Therefore,in this paper,the stability and dynamics of positive-negative vortex superposed states of two-dimensional exciton-polariton condensate in the disordered potential are studied under the rotation of the semiconductor microcavity,thereby laying a foundation for studying the gyroscopic effect of the superposed state of exciton-polariton condensates in the semiconductor microcavity.On the basis of reconstructing the mono-component Gross-Pitaevskii equation under the rotational situation,a numerical model with Coriolis items is constructed by the Runge-Kutta method and the finite difference time domain method,which is capable of depicting the rotation of the system.Moreover,the real-time evolution process of positive-negative vortex superposed states with different topological charges and the relationship between the number of steady-state local particles and the angular speed of the rotation of semiconductor microcavity are investigated by the real-time evolution method when the semiconductor microcavity is rotated.In the meantime,the relationship between the rotation speed in the excitation of vortex superposed states and the rotation speed of the semiconductor microcavity is also studied in the presence of the influence of the rotation speed of the semiconductor microcavity on the phase stability of vortex superposed states.According to the study,the rotation speed of the semiconductor microcavity has a significant influence on the evolution process and dynamic characteristics of vortex superposed states of excitonpolariton condensates.The rotation of the exciton-polariton system will accelerate the evolution of superimposed vortices,and overly rapid rotary rate will signalize the fluctuation of the local particle number thus the system unstability occurs.Moreover,along with the system rotation,the exciton-polariton superimposed vortices begin to rotate when the evolution approaches to saturation.It is noticeable that the angular acceleration of superimposed vortices is positively associated with the system rotary rate.Further,the topological charge has a significant influence on the rotation rate of exciation region of superposition state of vortices that it rotates more slowly when the topological charge increases but lower evolution stability simultaneously.These findings possess important guiding significance for establishing the quantum gyroscope in the future.