论文标题
开放式浮标系统的动态重新归一化群体理论
Dynamic renormalization group theory for open Floquet systems
论文作者
论文摘要
我们在开放式浮雕系统中开发了一种综合的重新归一化组（RG）方法，在该系统中，耗散使系统能够达到有限熵的浮力稳态，并且所有可观察到的物品都与驱动器同步。我们提供了有关如何结合Keldysh和Floquet形式主义的详细描述，以说明弱和快速驱动的制度的关键波动。一个关键的见解是，将时间平均，静态部门的减少不可能接近临界点。这指导着扰动动态RG方法的设计，该方法将与驱动器的较高谐波相关的时间依赖性，动态扇区在与时间平均的扇区相等的基础上。在此框架内，我们开发了一个弱驱动器扩展方案，该方案可以系统地截断RG流动方程的逆驱动频率$ω^{ - 1} $。这使我们可以展示定期驱动器如何抑制速度驱动的开放系统中二阶相变的规模不变性和临界波动：尽管临界点在极限$ω^{ - 1} = 0 $中出现，但任何有限驱动频率都会产生一个量表，该规模在整个相转换过程中均保持有限。这是一种普遍的机制，依赖于问题的静态和动态部门中关键波动的竞争。
We develop a comprehensive Renormalization Group (RG) approach to criticality in open Floquet systems, where dissipation enables the system to reach a well-defined Floquet steady state of finite entropy, and all observables are synchronized with the drive. We provide a detailed description of how to combine Keldysh and Floquet formalisms to account for the critical fluctuations in the weakly and rapidly driven regime. A key insight is that a reduction to the time-averaged, static sector, is not possible close to the critical point. This guides the design of a perturbative dynamic RG approach, which treats the time-dependent, dynamic sector associated to higher harmonics of the drive, on an equal footing with the time-averaged sector. Within this framework, we develop a weak drive expansion scheme, which enables to systematically truncate the RG flow equations in powers of the inverse drive frequency $Ω^{-1}$. This allows us to show how a periodic drive inhibits scale invariance and critical fluctuations of second order phase transitions in rapidly driven open systems: Although criticality emerges in the limit $Ω^{-1}=0$, any finite drive frequency produces a scale that remains finite all through the phase transition. This is a universal mechanism that relies on the competition of the critical fluctuations within the static and dynamic sectors of the problem.
