通过连续监控诱导并增强众多体量子混沌

对于众多体量子混沌，直觉上认为持续监控会抑制甚至破坏其混沌性，这一观点得到了早期研究的支持。我们在这里表明，情况并非如此。为此目的，我们研究了受持续监控影响的 Sachdev-Ye-Kitaev (SYK) 模型的退化动力学，采用 Lindblad 形式描述，耦合到由另一个常温 SYK 模型的热环境。我们发现，监控和热浴的综合效应会使系统趋向独立于初始条件的非热稳定态。相应的retarded Green's function exhibits two stages of exponential decay, with rates that depend non-monotonously on the thermal bath coupling and the monitoring strength. In the limit of weak coupling, the late time decay of the Green's function, computed analytically, is closely related to that of the thermal bath. Strikingly, we identify a range of parameters in which continuous monitoring, despite being a source of decoherence, induces or enhances quantum chaotic dynamics suppressed by the thermal bath. For instance, in the limit of weak coupling to the thermal bath, the Lyapunov exponent increases sharply when monitoring is turned on. For intermediate values of the thermal bath coupling, the Lyapunov exponent exhibits re-entrant behavior: it vanishes at zero or sufficiently weak monitoring strength, and becomes positive again as the monitoring strength is increased. Our results offer intriguing insights on the mechanisms leading to quantum scrambling which paves the way to its experimental control and consequently to a performance enhancement of quantum information devices.