Cookson Tamsin, Kalinin Kirill, Sigurdsson Helgi, Töpfer Julian D, Alyatkin Sergey, Silva Matteo, Langbein Wolfgang, Berloff Natalia G, Lagoudakis Pavlos G
Skolkovo Institute of Science and Technology, Skolkovo, Russian Federation.
Department of Physics and Astronomy, University of Southampton, Southampton, UK.
Nat Commun. 2021 Apr 9;12(1):2120. doi: 10.1038/s41467-021-22121-3.
Vorticity is a key ingredient to a broad variety of fluid phenomena, and its quantised version is considered to be the hallmark of superfluidity. Circulating flows that correspond to vortices of a large topological charge, termed giant vortices, are notoriously difficult to realise and even when externally imprinted, they are unstable, breaking into many vortices of a single charge. In spite of many theoretical proposals on the formation and stabilisation of giant vortices in ultra-cold atomic Bose-Einstein condensates and other superfluid systems, their experimental realisation remains elusive. Polariton condensates stand out from other superfluid systems due to their particularly strong interparticle interactions combined with their non-equilibrium nature, and as such provide an alternative testbed for the study of vortices. Here, we non-resonantly excite an odd number of polariton condensates at the vertices of a regular polygon and we observe the formation of a stable discrete vortex state with a large topological charge as a consequence of antibonding frustration between nearest neighbouring condensates.
涡度是多种流体现象的关键要素，其量子化形式被认为是超流性的标志。对应于大拓扑电荷涡旋的环流，即所谓的巨型涡旋， notoriously难以实现，即使是外部施加的，它们也是不稳定的，会分裂成许多单电荷涡旋。尽管在超冷原子玻色 - 爱因斯坦凝聚体和其他超流系统中关于巨型涡旋的形成和稳定有许多理论提议，但它们的实验实现仍然难以捉摸。极化激元凝聚体因其特别强的粒子间相互作用及其非平衡性质而在其他超流系统中脱颖而出，因此为涡旋研究提供了一个替代试验台。在这里，我们在正多边形的顶点非共振地激发奇数个极化激元凝聚体，并且我们观察到由于最近邻凝聚体之间的反键受挫而形成了具有大拓扑电荷的稳定离散涡旋态。
