From diffusion experiments to mean-field theory simulations and back

M. DI PIETRO MARTÍNEZ; M. HOYUELOS

Buenos Aires

Congreso; StatPhys27; 2019

We considered a mean-field approach to diffusion of interacting particles.In this model, the system is divided in cells and transition probabilities between neighboring cells depend on a mean-field potential V that represents the potential for one particle generated by the presence of all the others. An important ingredient of this approach is an interpolation parameter &theta that determines if the transition probability of a particle, that jumps from a position to another, depends on the mean-field potential at the origin position, the target position, or a combination of both. In this sense, measuring &theta will allow to understand the underlying dynamics of diffusion processes with a simple and minimal model. Here, we show that there is a link between the mean-field parameters, V and &theta, and  the experimental observables, such as the activity and the single-particle diffusion coefficient.We gathered previous experimental data of diffusion in metallic alloys in order to obtain real values for V and &theta. As a final test, we reobtain, with all this information as an input to our Monte Carlo simulations, the collective diffusion coefficient for the studied metallic alloys. Therefore, the method provides appropriate transition probabilities to perform Monte Carlo simulations that correctly describe the out of equilibrium behavior.