Calculation of the fluctuation-dissipation ratio for the nonequilibrium critical behavior of disordered systems

Influence of disorder on ageing and memory effects in non-equilibrium critical dynamics of 3D Ising model relaxing from an ordered state

“…The obtained data are plotted in figure 6 for dierent spin concentrations p. One can see that the dependence of χ T versus C has for pure systems in figure 6 [20] with the use of the RG analysis and ε-expansion method for description of the non-equilibrium critical dynamics of the dissipative model A. In the case of evolution from the high-temperature initial state, the non-equilibrium critical dynamics of the 3D pure Ising model is characterized by considerably dierent asymptotic values of the FDR ( ) = ∞ X 0.380 13 [17]. Prognosticated values of ∞ X for other initial states with 0 < m 0 <1 are in interval from 0.380 to 0.784.…”

“…For simulation of the site-diluted 3D Ising model, starting from the completely ordered initial state with m 0 = 1, we used the thermal bath algorithm [27]. Instead of the response function in (3), we calculated the dynamical susceptibility as the integrated response function (also well known as thermoremanent magnetization) using the relations [17,20]…”

“…Up to now, the study of the non-equilibrium critical behaviour of dierent statistical systems has been performed in the most complete form only for the case of their evolution from the initial high-temperature state (see review [3]). In papers [17][18][19] we have carried out Monte Carlo investigations of influence of disorder on the non-equilibrium critical relaxation of the 3D site-diluted Ising model prepared in a high-temperature initial state. The ageing eects were investigated and the values of the asymptotic fluctuation-dissipation ratio (FDR) ∞ X were calculated for systems with dierent spin concentrations.…”

Study of laser cooling in deep optical lattice: two-level quantum model

“…Really, the semiclassical models can't be applied here because of the velocity range of the semiclassical damping force on Mg atoms has sharp variation in momentum space ∆p ≪hk (see figure 3). As well the semiclassical parameter ε R =hk 2 /(2Mγ) ≫ 1 is not small, that also contradicts requirements for semiclassical approach [1,13,14]. For description of laser cooling of Mg in the optical trap we consider two quantum approaches.…”

Peculiarities of Non-Equilibrium Critical Behavior for 3D Diluted Ising Model with Evolution from Low-Temperature Initial State

“…At first, it was shown, that pinning of domain walls on defects leeds to a sharp change of aging properties in diluted systems in comparison with pure system. Therefore, the asymptotic value of the fluctuation-dissipative ratio ∞ X becomes equal to zero for diluted systems, while for pure system ∞ X = 0.784 (5).…”