Paschos G G, Tzimis A, Tsintzos S I, Savvidis P G
Westlake University, 18 Shilongshan Rd, Hangzhou 310024, Zhejiang, People's Republic of China.
Westlake Inst Adv Study, National Institute of Sciences, 18 Shilongshan Rd, Hangzhou 310024, Zhejiang, People's Republic of China.
J Phys Condens Matter. 2020 Jun 17;32(36). doi: 10.1088/1361-648X/ab9267.
Spatially confined, trapped polariton condensates have been shown to exhibit strong stochastic on-site spin polarization and in longer polariton condensate chains, distance controlled ferromagnetic and antiferromagnetic spin couplings. Until now, little is known, on how such polariton condensates spatially separated from their exciton reservoirs are trapped and formed. Here, we investigate the properties and formation dynamics of two main families of polariton condensates, those overlapping with the pump reservoir and those in confined geometries, under pulsed nonresonant excitation. The observed reduction in polariton condensation threshold and energy blueshift in trapped case is attributed to exciton reservoir-condensate spatial separation, whereas time-resolved photoluminescence measurements, reveal distinct relaxation and condensate formation dynamics with pair parametric scattering process being the dominant relaxation mechanism in trapped geometry.
空间受限的捕获极化激元凝聚体已被证明表现出强烈的随机局域自旋极化，并且在较长的极化激元凝聚体链中表现出距离可控的铁磁和反铁磁自旋耦合。到目前为止，对于这些与激子库在空间上分离的极化激元凝聚体是如何被捕获和形成的，人们了解甚少。在这里，我们研究了在脉冲非共振激发下，两类主要的极化激元凝聚体的性质和形成动力学，即与泵浦库重叠的凝聚体和处于受限几何结构中的凝聚体。在捕获情况下观察到的极化激元凝聚阈值降低和能量蓝移归因于激子库 - 凝聚体的空间分离，而时间分辨光致发光测量揭示了不同的弛豫和凝聚体形成动力学，其中对参量散射过程是受限几何结构中的主要弛豫机制。
