基于双原子超-亚辐射态选择性驱动的空间定向关联辐射  

Spatially oriented correlated emission based on selective drive of diatomic superradiance states

作　　者：张杰 陈爱喜 彭泽安 Zhang Jie Chen;Ai-Xi;Peng Ze-An(School of Science,Zhejiang Sci-Tech University,Hangzhou 310018,China)

机构地区：[1]浙江理工大学理学院,杭州310018

出　　处：《物理学报》2024年第14期87-98,共12页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12204414,12175199)资助的课题.

摘　　要：对于两个二能级原子组成的系统,当受到方向性可调的激光场驱动,同时原子间存在偶极-偶极相互作用和自发辐射相干的条件下,我们研究系统的双光子发射现象.对于全同原子系统,原子在特殊的几何构型下,能够实现将原子系统选择性激发到超辐射态或亚辐射态,详细讨论了关联函数的角分布情况.对于非全同原子系统,由于原子间的失谐,选择性驱动减弱,但是通过失谐的改变,激光方向调节能够对能级间耦合强度产生显著影响.研究发现调整激光的入射角度和原子的失谐,能够改变原子一阶相干,进而可以优化关联函数的角分布图样,以获得良好的对称性.本研究能够实现单侧或双侧高定向双光子发射,这为纳米天线的双光子发射提供了理论依据.In recent years,the radiative properties of atomic systems have been a hot topic in the research fields of quantum optics and quantum information.With the continuous development of nanophotonics,quantum antennas have become an important model for studying atomic radiation.In order to investigate these phenomena in depth,we investigate a system composed of two two-level atoms,and study the two-photon emission phenomenon of diatomic system under conditions of driving directional tunable laser field,interatomic dipole-dipole interaction,and spontaneous emission coherence.In this study,we diagonalize the atomic Hamiltonian to obtain the eigenvalues and entangled states of the system(symmetric and asymmetric states of two atoms),and use the rotating wave approximation to rotate the system into the laser frame.The evolution of the system is characterized mainly by the evolution of symmetric and asymmetric state,as well as the evolution of coherent terms.In our studies it is found that for identical atoms,certain laser directions and geometric configurations can exclusively drive the superradiant and subradiant states of atoms,which can enhance the first-order interference effect of the atoms and markedly increase the probability of two-photon emission in a specific detection direction.When the superradiant state of the atom is solely driven,there will be no coupling between the superradiant state and subradiant state,resulting in a correlation function angular distribution that is symmetric along the direction perpendicular to atomic axis.Further adjusting the laser direction causes the atomic interference patterns to shift,and the system will exhibit two-photon emission characteristics on one side or both sides.For nonidentical atomic systems,due to detuning between the two atoms,the laser cannot drive the superradiant state or subradiant state individually,and the influence of changing the laser direction on the coupling strength diminishes with the increase of detuning between the atoms.When the laser is in resonanc

关 键 词：超辐射 亚辐射 光子关联 纳米天线 

分 类 号：O431.2[机械工程—光学工程]