Signatures of a dissipative phase transition in photon correlation measurements
Signatures of a dissipative phase transition in photon correlation measurements
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DOI：
10.1038/s41567-017-0020-9
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发表时间：
2018-04-01
期刊：
影响因子：
19.6
通讯作者：
Imamoglu, Atac
中科院分区：
文献类型：
--
作者：
Fink, Thomas;Schade, Anne;Imamoglu, Atac
理解和表征驱动耗散系统中的相变构成了多体物理学的一个新领域（1-8）。耗散相变的一个普遍特征是Liouvillian谱中的消失间隙（9），当系统被驱动向相变时，这导致长期偏离稳态。在这里，我们表明，光子相关测量可以用来表征相应的临界减慢的非平衡动力学。我们集中研究了GaAs腔极化激元中广泛研究的光学双稳现象（10，11），它可以被描述为一阶耗散相变（12-14）。随着激发强度的增加，光子聚束信号沿着增加，其衰减时间比单极化激元延长了9个数量级以上。在强极化激元相互作用导致明显的量子涨落的极限下，平均场双稳阈值被冲掉。然而，功能的形式与Liouvillian间隙关闭的热力学极限接近提供了一个签名的新兴耗散相变。我们的研究结果建立光子相关测量作为一个宝贵的工具，研究耗散相变的动力学性质，而不需要相敏干涉测量。
Understanding and characterizing phase transitions in drivendissipative systems constitutes a new frontier for many-body physics(1-8). A generic feature of dissipative phase transitions is a vanishing gap in the Liouvillian spectrum(9), which leads to long-lived deviations from the steady state as the system is driven towards the transition. Here, we show that photon correlation measurements can be used to characterize the corresponding critical slowing down of non-equilibrium dynamics. We focus on the extensively studied phenomenon of optical bistability in GaAs cavity polaritons(10,11), which can be described as a first-order dissipative phase transition(12-14). Increasing the excitation strength towards the bistable range results in an increasing photon-bunching signal along with a decay time that is prolonged by more than nine orders of magnitude as compared with that of single polaritons. In the limit of strong polariton interactions leading to pronounced quantum fluctuations, the mean-field bistability threshold is washed out. Nevertheless, the functional form with which the Liouvillian gap closes as the thermodynamic limit is approached provides a signature of the emerging dissipative phase transition. Our results establish photon correlation measurements as an invaluable tool for studying dynamical properties of dissipative phase transitions without requiring phase-sensitive interferometric measurements.