Joshi M K, Kranzl F, Schuckert A, Lovas I, Maier C, Blatt R, Knap M, Roos C F
Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Technikerstraße 21a, 6020 Innsbruck, Austria.
Institut für Experimentalphysik, Universität Innsbruck, Technikerstraße 25, 6020 Innsbruck, Austria.
Science. 2022 May 13;376(6594):720-724. doi: 10.1126/science.abk2400. Epub 2022 May 12.
Identifying universal properties of nonequilibrium quantum states is a major challenge in modern physics. A fascinating prediction is that classical hydrodynamics emerges universally in the evolution of any interacting quantum system. We experimentally probed the quantum dynamics of 51 individually controlled ions, realizing a long-range interacting spin chain. By measuring space-time-resolved correlation functions in an infinite temperature state, we observed a whole family of hydrodynamic universality classes, ranging from normal diffusion to anomalous superdiffusion, that are described by Lévy flights. We extracted the transport coefficients of the hydrodynamic theory, reflecting the microscopic properties of the system. Our observations demonstrate the potential for engineered quantum systems to provide key insights into universal properties of nonequilibrium states of quantum matter.
识别非平衡量子态的普遍性质是现代物理学中的一项重大挑战。一个引人入胜的预测是，经典流体动力学在任何相互作用量子系统的演化中普遍出现。我们通过实验探测了51个单独控制的离子的量子动力学，实现了一个长程相互作用自旋链。通过测量无限温度状态下的时空分辨关联函数，我们观察到了一整个流体动力学普适类家族，范围从正常扩散到反常超扩散，它们由 Lévy 飞行描述。我们提取了流体动力学理论的输运系数，反映了系统的微观性质。我们的观察结果表明，工程量子系统有潜力为量子物质非平衡态的普遍性质提供关键见解。
