Bessel型光晶格中自旋-轨道耦合极化激元凝聚的稳态结构

Stationary structures of spin-orbit coupled polariton condensates in Bessel lattices

Bessel型光晶格是一种非空间周期性的柱对称的光晶格势场,其兼具无限深势阱和环状势阱的特征,在0阶Bessel光晶格势场中央形成深势阱,而在非0阶Beseel光晶格势场中能形成具有中央势垒的环状浅势阱.极化激元是一种半光半物质的准粒子,该准粒子甚至可以在室温条件下发生玻色-爱因斯坦凝聚相变,形成极化激元凝聚.另外,通过极化激元能级的腔诱导TE-TM分裂能在极化激元凝聚中实现足够强的自旋-轨道耦合作用.极化激元凝聚能在室温条件下实现,在其中又存在自旋-轨道耦合作用,其为量子物理的研究提供了全新的平台.本文把Bessel光晶格势场引入到极化激元凝聚系统,研究了存在自旋-轨道耦合作用下的旋量双组分极化激元凝聚系统的稳态结构.通过求解Gross-Pitaevskii方程给出了极化激元凝聚系统在实验室坐标系和旋转坐标系中极化激元凝聚系统的稳态结构,由于Bessel势场的引入,使得稳态结构更具有多样性.给出了实验室坐标系中在中央深势阱中存在的基础型高斯孤立子、多极孤立子和在环状浅势阱中存在环状孤立子和多极孤立子的稳态结构;给出了旋转坐标系中存在的涡旋环状孤立子,及其由于自旋-轨道相互作用引起的组分分离的稳态结构.分析了自旋-轨道耦合作用对两种坐标系中稳态结构的影响和多极孤立子在旋转坐标系中的稳定性.结果表明,环状浅势阱中形成的多极孤立子相对于中央深势阱中形成的多极孤立子具有更好的稳定性,它们在旋转过程中能够长时间保持相对结构和空间分布不变.在旋转坐标系中,即使不满足双组分组分分离的条件,由于自旋-轨道耦合作用的引入也能使得两组分发生组分分离.

Bessel optical lattice yields a non-spatially periodic column-symmetric optical lattice potential field,which has the characteristics of both infinite deep potential well and the ring-shaped potential well.A deep potential is formed in the center of the 0-order Bessel optical lattice.In the non-zero-order Beseel optical lattice,a ringshaped shallow potential well with a central barrier can be formed.Exciton-polariton is a semi-light and semimatter quasi-particle,which can achieve the Bose-Einstein condensate phase transition even at room temperature to form a polariton condensate.In addition,the polariton condensate is likely to realize sufficiently strong spin-orbit coupling due to the cavity-induced TE-TM splitting of the polariton energy levels.The polariton condensate can be realized at room temperature,and there can be spin-orbit coupling in it,which provides a new platform for the studying of quantum physics.In this paper,the Bessel optical lattice is introduced into a polariton condensate.The stationary state structure of spinor two-component polariton condensate with spin-orbit coupling is investigated.By solving the Gross-Pitaevskii equation,we first give a stationary state structures of the polariton condensate both in the laboratory coordinate frame and in the rotating coordinate frame.Owing to the introduction of the Bessel optical lattice,the stationary state structures of polariton condensate are diverse.We dispaly the stationary state structures of the basic Gaussian solitons and multipole solitons in the central deep potential well in the laboratory coordinate frame,and the ring solitons and multipole solitons in the central shallow potential well.We also dispaly the vortex ring soliton that exists in the rotating coordinate frame,and the stationary state structure of the component separation caused by the spin-orbit interaction.We analyze not only the influences of the spin-orbit coupling on the stationary state structures in the two coordinate frames,but also the stability of the multipole solitons in the rotating coordinate frame.It is found that the multipole solitons formed in the ring-shaped shallow potential well have better stability than in the central deep potential well,and they can maintain the relative structure and spatial distribution for a long time in the rotation process.In the rotating coordinate frame,even if the two-component separation conditions are not satisfied,the introduction of spinorbit coupling can cause the two components to separate.