David Mukamel – The Weizmann Institute
Wednesday, February 12th , 10:45AM EST
Local drive and long-range correlations in interacting diffusive systems
The long-range nature of the nonequilibrium steady state resulting from a local drive (a pump or a battery) is discussed in the context of interacting diffusive fluid. It is shown that under generic, non-critical conditions, the pump generates long-range modulation in the density profile of the form of a dipolar electric potential, and a current profile in the form of a dipolar electric field. It also induces long-range density correlations.
The density profile is drastically modified when the fluid is at its critical point: here, in addition to the long-rage influence of the current generated by the local drive, the fluid is also dominated by its intrinsic long- range critical correlations. It is demonstrated that the resulting density profile can be mapped onto that of an equilibrium fluid under the influence of a long-ranged dipolar potential. This mapping to an equilibrium system allows one to express the nonequilibrium density profile at criticality in terms of the equilibrium critical exponents of the fluid. In contrast, the current is shown to retain it off critical dipolar field form.