Shearing a glassy material: Numerical tests of nonequilibrium mode-coupling approaches and experimental proposals

The predictions of a nonequilibrium schematic mode-coupling theory developed to describe the nonlinear rheology of soft glassy materials have been numerically tested in a sheared binary Lennard-Jones mixture. In this Letter, we focus on the existence, behavior, and properties of an effective temperature T-eff for the slow modes of the fluid, as defined from a generalized fluctuation-dissipation theorem. New, simple experimental protocols to access T-eff are proposed, and one such experiment is numerically performed. Our results give strong support to the thermodynamic interpretation of T-eff and make it experimentally accessible in a very direct way.