The existence of quantized vortices is a key feature of Bose–Einstein condensates. In equilibrium condensates, only quantum vortices of unit topological charge are stable, due to the dynamical instabilities of multiply charged defects, unless supported by strong external rotation. Due to immense interest in the physics of these topological excitations, a great deal of work has been done to understand how to force their stability. Here we show that in photonic Bose–Einstein condensates of exciton–polariton quasiparticles pumped in an annular geometry, not only do the constant particle fluxes intrinsic to the system naturally stabilize multiply charged vortex states, but that such states can indeed form spontaneously during the condensate formation through a dynamic symmetry breaking mechanism. We elucidate the properties of these states, notably finding that they radiate acoustically at topologically quantized frequencies. Finally, we show that the vorticity of these photonic fluids is limited by a quantum Kelvin–Helmholtz instability, and therefore by the condensate radius and pumping intensity. This reported instability in a quantum photonic fluid represents a fundamental result in fluid dynamics.

中文翻译：

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极化子冷凝物的带电涡旋态

量化涡旋的存在是Bose-Einstein冷凝物的关键特征。在平衡冷凝物中，除非多重带电缺陷的动力学不稳定性，否则除非具有强烈的外部旋转，否则只有单位拓扑电荷的量子涡旋才是稳定的。由于对这些拓扑激发的物理学有极大的兴趣，因此进行了大量工作以了解如何增强其稳定性。在这里，我们表明，在以环形几何形状泵浦的激子-极化子准粒子的光子玻色-爱因斯坦凝聚物中，系统固有的恒定粒子通量不仅使多电荷涡态自然稳定，而且在凝聚过程中这些态的确可以自发形成通过动态对称破坏机制形成。我们阐明了这些状态的性质，特别是发现它们以拓扑量化的频率发声。最后，我们表明，这些光子流体的涡度受到量子开尔文-亥姆霍兹不稳定性的限制，因此受到凝结半径和泵浦强度的限制。报告的量子光子流体的不稳定性代表了流体动力学的根本结果。