Out-of-Equilibrium Processes

Roberto Livi, Paolo Politi

Rouven Frassek, Jan de Gier, Jimin Li +1 more

Duality transformations reveal unexpected equivalences between seemingly distinct models. We introduce an out-of-equilibrium generalisation of matrix product operators to implement duality transformations in one-dimensional boundary-driven Markov processes on lattices. In contrast to local dualities associated with generalised symmetries, here the duality operator intertwines two Markov processes via generalised exchange relations and realises the out-of-equilibrium duality globally. We construct these operators exactly for the symmetric simple exclusion process with distinct out-of-equilibrium boundaries. In this case, out-of-equilibrium boundaries are dual to equilibrium boundaries satisfying Liggett's condition, implying that the Gibbs-Boltzmann measure captures out-of-equilibrium physics when leveraging the duality operator. We illustrate this principle through physical applications.

CHEN XIAO-YUAN, Xiwen Zhu, 中国科学院武汉物理研究所

We obtained the conditions under which the maximum non-equilibrium distribution of the population of alkali atoms in the ground state in atomic beam pumped by laser-MW double resonance is achieved. These conditions are consistent with recent experiments. We examined the processes which affect the realization of the non-equilibrium distribution of population, and indicated the methods of eliminating the effects of these processes. The features of pumping processes with laser-MW double resonances are discussed, and compared with the two laser pumping process.

Dmitry A. Ryndyk

André F. Verbeure

Nobuyasu Ito, Keita Ogawa, Koji Hukushima +1 more

It is shown that the non-equilibrium relaxation (NER) process of the order-parameter and energy is useful to study the phase transition.By observing the log-derivatives of those decay functions, the critical point is located finely and the critical exponents are estimated accurately.The major advantage of NER method is it's simplicity; not only the behavior in the large-size limit can be observed easily, but also it is not necessary to pursue the equilibrium of the system to get information of the final equilibrium state.Applications are expanding from basic systems like Ising ferromagnets, to spin-glass, quantal system, chiral and KT transitions, and so on.Now the NER process of fluctuations is also expected to share those advantages.It is found that the combinations of the NER functions of some fluctuations provide the way to determine static and dynamics critical exponents directly.