Penrose processes in an analogue black hole formed in hybrid light-matter (polariton) superfluid

由于极端的引力，没有任何东西，甚至光，可以从黑洞中逃脱。然而，正如罗杰·彭罗斯（Roger Penrose）所展示的，大质量粒子进入视界外的经过区，可以从旋转的黑洞中汲取能量。我们建议在半导体微腔极化平台中形成的桌面实验量子光物质超流体中探索这个难以捉摸的迷人过程；这将在微观尺度上模拟2+1维模拟时空中的旋转黑洞。该研究将利用极化子系统非常有利的特性，如由于巨大的光学非线性而经历冷凝和超流体的能力，以及使用外部激光源控制、驱动和测量二维极化子的空间密度和相位的能力。这使得黑洞中时空的“流动”可以通过超流体中的一个巨大的排水漩涡来模拟，在那里，从亚音速到超音速流动的过渡边界重现了事件视界。本提案的特别重点将放在研究彭罗斯过程如何受到极化流体（由宏观有序描述）的量子行为的影响，从而导致模拟黑洞的轨道角动量的量子化。总的来说，我们的项目通过利用物理系和谢菲尔德大学国家外延研究所开发的最先进的半导体量子技术来解决基础物理问题：它将广义相对论与固体中宏观有序光物质状态的流体动力学和物理学联系起来，并为微观尺度上的量子现象和引力效应的研究开辟了新的途径。

Nothing, not even light, can escape from a black hole due to extreme gravity. However, as was shown by Roger Penrose , massive particles entering the ergoregion just outside the event horizon can extract energy from a rotating black hole. We propose to explore this elusive, fascinating process in a table-top experimental quantum light-matter superfluid formed in a semiconductor microcavity polariton platform; this will emulate a rotating black hole in 2+1 dimensional analogue spacetime on a microscale. The research will capitalize on the highly favorable properties of the polariton system, such as the ability to undergo condensation and superfluidity due to the giant optical nonlinearity, as well as the ability to control, drive and measure the spatial density and phase of the 2D polaritons using external laser sources. These enable the "flow" of space-time in a black hole by a large draining vortex in a superfluid to be emulated, where the boundary of the transition from subsonic to supersonic flow recreates the event horizon. The particular focus of this proposal will be on the study of how the Penrose process is affected by the quantum behavior of the polariton fluid (described by macroscopic order) leading to quantization of orbital angular momentum of the analogue black hole. Overall our project addresses fundamental physics questions by exploiting state-of-the art semiconductor quantum technologies developed in the Physics Department and at the National Epitaxy Facility at the University of Sheffield: it relates general relativity to hydrodynamics and physics of macroscopically ordered light-matter states in solids and opens up new avenues in the study of quantum phenomena and gravity effects on the microscale.