耗散随机系统中的随机泵效应和几何相位

Geometric Heat Pump: Controlling Thermal Transport with Time-dependent Modulations

The second law of thermodynamics dictates that heat simultaneously flows from the hot to cold bath on average. To go beyond this picture, a range of works in the past decade show that, other than the average dynamical heat flux determined by instantaneous thermal bias, a non-trivial flux contribution of intrinsic geometric origin is generally present in temporally driven systems. This additional heat flux provides a free lunch for the pumped heat and could even drive heat against the bias. We review here the emergence and development of this so called ``geometric heat pump'', originating from …

经典耗散系统绝热参数变化下的Hannay角和几何相移

Hannay angle and geometric phase shifts under adiabatic parameter changes in classical dissipative systems

In Phys. Rev. Lett. { \bf 66}，847（1991），T. B. Kepler和M. L. Kagan导出了耗散极限环演化中的几何相移。这种效应被认为是经典力学中几何相位的推广。我们发现，反过来也是如此，即，这个几何相位可以确定与经典的机械Hannay角在一个扩展的相空间。我们的研究结果表明，这个阶段可以推广到一个随机演化与一个额外的噪声项的演化方程。

Pseudo-thermalization in driven-dissipative non-Markovian open quantum systems

We investigate a `pseudo thermalization' effect, where an open quantum system coupled to several non-Markovian reservoirs presents an emergent thermal behaviour in spite of its coupling to a non-equilibrated environment. The thermal behaviour is visible at both static and dynamical levels and the system satisfies the fluctuation-dissipation theorem. Our analysis is focused on the exactly solvable model of a weakly interacting driven-dissipative Bose gas in presence of frequency-dependent particle pumping and losses, and is based on a quantum Langevin theory, which we derive starting from a mic…

Shortcuts to Adiabatic Pumping in Classical Stochastic Systems

Adiabatic pumping is characterized by a geometric contribution to the pumped charge, which can be non-zero even in the absence of a bias. However, as the driving speed is increased, non-adiabatic excitations gradually reduce the pumped charge, thereby limiting the maximal applicable driving frequencies. To circumvent this problem, we here extend the concept of shortcuts to adiabaticity to construct a control protocol which enables geometric pumping well beyond the adiabatic regime. Our protocol allows for an increase, by more than an order of magnitude, in the driving frequencies, and the meth…

Study of quantum Otto heat engine using driven-dissipative Schrödinger equation

The quantum heat engines have drawn much attention due to miniaturization of devices recently. We study the dynamics of the quantum Otto heat engine using the driven-dissipative Schrödinger equation. Starting from different initial states, we simulate the time evolutions of the internal energy, power and heat-work conversion efficiency. The initial state impacts on these thermodynamic quantities before the Otto cycle reaches stable. In the transition period, the efficiency and power may be higher or lower than the corresponding values in the cyclostationary state. Remarkably, the efficiency co…

Competing coherent and dissipative dynamics close to quantum criticality

We investigate the competition of coherent and dissipative dynamics in many-body systems at continuous quantum transitions. We consider dissipative mechanisms that can be effectively described by Lindblad equations for the density matrix of the system. The interplay between the critical coherent dynamics and dissipation is addressed within a dynamic finite-size scaling framework, which allows us to identify the regime where they develop a nontrivial competition. We analyze protocols that start from critical many-body ground states and put forward general dynamic scaling behaviors involving the…

受驱动耗散超导体中的迈斯纳效应与约瑟夫森辐射

Meissner Effect and Josephson Radiation in Driven Dissipative Superconductors

本研究提出受驱动耗散超导机制解释光诱导超导特征，构建耦合序参量的连续介质理论，通过约瑟夫森结实验验证其迈斯纳效应与辐射特征，可区分非平衡与平衡超导态。

Dissipative Two-Mode Tavis-Cummings Model with Time-Delayed Feedback Control

We investigate the dynamics of a two-mode laser system by extending the two-mode Tavis-Cummings model with dissipative channels and incoherent pumping and by applying the mean-field approximation in the thermodynamic limit. To this end we analytically calculate up to four possible non-equilibrium steady states (fixed points) and determine the corresponding complex phase diagram. Various possible phases are distinguished by the actual number of fixed points and their stability. In addition, we apply three time-delayed Pyragas feedback control schemes. Depending on the time delay and the strengt…