Department of Physics and Center for Optoelectronics and Photonics Paderborn (CeOPP), Universität Paderborn, Warburger Strasse 100, 33098 Paderborn, Germany.
College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, USA.
Phys Rev Lett. 2018 Nov 30;121(22):227404. doi: 10.1103/PhysRevLett.121.227404.
Vortices are topological objects formed in coherent nonlinear systems. As such they are studied in a wide number of physical systems and promise applications in information storage, processing, and communication. In semiconductor microcavities, vortices in polariton condensates can be conveniently created, studied, and manipulated using solely optical means. For nonresonant excitation with a ring-shaped pump a stable vortex can be formed, leading to bistability with left- and right-handed vorticity. In the present work we report on a much richer vortex multistability, with optically addressable vortices with topological charges m=±1, ±2, and ±3, all stable for the same system and excitation parameters. This unusual multistable behavior is rooted in the inherent nonlinear feedback between reservoir excitations and condensate in the microcavity. For larger radius of the ring-shaped pump we also find a Bessel vortex with its characteristic spiralling phase in the high density region and pronounced self-stabilization ability. Our theoretical results open up exciting possibilities for optical manipulation of vortex multiplets in a compact semiconductor system.
涡旋是在相干非线性系统中形成的拓扑物体。因此，它们在许多物理系统中得到了研究，并有望在信息存储、处理和通信中得到应用。在半导体微腔中，可以仅使用光学手段方便地创建、研究和操纵极化激元凝聚体中的涡旋。对于具有环形泵浦的非共振激发，可以形成稳定的涡旋，导致具有左右旋度的双稳性。在目前的工作中，我们报告了一种更为丰富的涡旋多稳性，具有可光学寻址的拓扑电荷 m=±1、±2 和±3 的涡旋，所有这些涡旋在相同的系统和激发参数下都是稳定的。这种不寻常的多稳性行为源于微腔中储层激发和凝聚体之间固有的非线性反馈。对于环形泵浦的更大半径，我们还发现了具有特征螺旋相位的贝塞尔涡旋，在高密度区域具有明显的自稳定能力。我们的理论结果为在紧凑的半导体系统中光学操纵涡旋多体开辟了令人兴奋的可能性。
