Kardar-Parisi-Zhang universality in a one-dimensional polariton condensate
Kardar-Parisi-Zhang universality in a one-dimensional polariton condensate
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DOI：
10.1038/s41586-022-05001-8
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发表时间：
2022-08-25
期刊：
影响因子：
64.8
通讯作者：
Bloch, Jacqueline
中科院分区：
文献类型：
--
作者：
Fontaine, Quentin;Squizzato, Davide;Bloch, Jacqueline
揭示普遍行为是统计物理学的一个标志。诸如晶体表面（1）和细菌菌落（2）中界面的随机生长，以及量子磁体（3-6）中的自旋输运等现象都属于同一普适类，尽管它们在微观水平上涉及大量的物理机制。更具体地说，在所有这些系统中，时空相关性表现出幂律标度，其特征在于普适临界指数。这种普遍性源于由非线性随机Kardar-Parisi-Zhang（KPZ）方程（7）控制的共同潜在有效动力学。最近的理论工作表明，这种动力学也出现在显示宏观自发相干性的非平衡系统阶段（8-17）。在这里，我们的实验证明，在一个驱动耗散一维极化激元凝聚体的相位的演变属于KPZ普适类福尔斯。我们的证明依赖于KPZ时空标度律的直接测量（18，19），结合揭示这一普适性类的其他关键特征的理论分析。我们的研究结果突出了平衡态凝聚体与平衡态凝聚体之间的基本物理差异，并为探索驱动开放量子系统中的普遍行为开辟了一个范例。
Revealing universal behaviours is a hallmark of statistical physics. Phenomena such as the stochastic growth of crystalline surfaces(1) and of interfaces in bacterial colonies(2), and spin transport in quantum magnets(3-6) all belong to the same universality class, despite the great plurality of physical mechanisms they involve at the microscopic level. More specifically, in all these systems, space-time correlations show power-law scalings characterized by universal critical exponents. This universality stems from a common underlying effective dynamics governed by the nonlinear stochastic Kardar-Parisi-Zhang (KPZ) equation(7). Recent theoretical works have suggested that this dynamics also emerges in the phase of out-of-equilibrium systems showing macroscopic spontaneous coherence(8-17). Here we experimentally demonstrate that the evolution of the phase in a driven-dissipative one-dimensional polariton condensate falls in the KPZ universality class. Our demonstration relies on a direct measurement of KPZ space-time scaling laws(18,19), combined with a theoretical analysis that reveals other key signatures of this universality class. Our results highlight fundamental physical differences between out-of-equilibrium condensates and their equilibrium counterparts, and open a paradigm for exploring universal behaviours in driven open quantum systems.