Confined molecules under shear: From a microscopic description to phenomenology

A coarse grained two-state model is derived starting from a molecular dynamics description of a molecular system under shear. This model captures the main features of the response of a confined system under shear, and generalizes the phenomenological Tomlinson model for the response of a driven system. The derivation is based on the solution of coupled microscopic equations using a mean field approximation. The two-state model agrees well with the direct numerical solution and offers a practical approach to investigate the response of sheared systems under a broad range of parameters.