近日，英国诺丁汉大学的Silke Weinfurtner&Patrik Svancara及其研究团队取得一项新进展。经过不懈努力，他们揭示巨型量子涡旋的旋转弯曲时空特征。相关研究成果已于2024年3月20日在国际权威学术期刊《自然》上发表。

该研究团队证实尽管多重量子化涡旋本身具有不稳定性，但静止的巨型量子涡旋却能在超流体⁴He中保持稳定。其紧凑的核心承载着数千个循环量子，这远远超越了目前其他物理系统（如磁振子、原子云和极化子等）所能达到的水平。本文还介绍了一种新颖的、最小侵入式的方法，通过利用超流体界面上微米尺度的波与背景速度场的相互作用，来表征涡旋流动。

在此过程中，研究人员观察到了复杂的波涡旋相互作用，包括束缚态的检测和独特的模拟黑洞振铃特征。这些发现不仅为探索量子到经典的涡旋相变提供了新的视角，也为使用超流氦作为旋转弯曲时空的有限温度量子场论模拟器开辟了新的途径。

据悉，重力模拟器是一种实验室系统，其中声音或表面波等微小激励会在弯曲的时空几何上传播，如同场一般。重力和流体之间的类比要求粘度消失，这一特性在超流体如液态氦或冷原子云中自然呈现。此类系统已成功在弯曲时空中验证了量子场论的关键预测。特别是，旋转弯曲时空的量子模拟表明天体物理黑洞需要实现超流体系统中的大涡旋流动。

附：英文原文

Title: Rotating curved spacetime signatures from a giant quantum vortex

Author: Svancara, Patrik, Smaniotto, Pietro, Solidoro, Leonardo, MacDonald, James F., Patrick, Sam, Gregory, Ruth, Barenghi, Carlo F., Weinfurtner, Silke

Issue&Volume: 2024-03-20

Abstract: Gravity simulators are laboratory systems in which small excitations such as sound or surface waves behave as fields propagating on a curved spacetime geometry. The analogy between gravity and fluids requires vanishing viscosity, a feature naturally realized in superfluids such as liquid helium or cold atomic clouds. Such systems have been successful in verifying key predictions of quantum field theory in curved spacetime. In particular, quantum simulations of rotating curved spacetimes indicative of astrophysical black holes require the realization of an extensive vortex flow in superfluid systems. Here we demonstrate that, despite the inherent instability of multiply quantized vortices, a stationary giant quantum vortex can be stabilized in superfluid ⁴He. Its compact core carries thousands of circulation quanta, prevailing over current limitations in other physical systems such as magnons, atomic clouds and polaritons. We introduce a minimally invasive way to characterize the vortex flow by exploiting the interaction of micrometre-scale waves on the superfluid interface with the background velocity field. Intricate wave–vortex interactions, including the detection of bound states and distinctive analogue black hole ringdown signatures, have been observed. These results open new avenues to explore quantum-to-classical vortex transitions and use superfluid helium as a finite-temperature quantum field theory simulator for rotating curved spacetimes.

DOI: 10.1038/s41586-024-07176-8

Source: https://www.nature.com/articles/s41586-024-07176-8