The instantaneous normal mode spectrum of a liquid undergoing shear flow

Abstract

The instantaneous normal mode spectrum of a Lennard-Jones liquid undergoing shear flow is determined as a function of shear rate. Shear flow is shown to deplete the density of states at low frequencies and augment the density of states at high frequencies, for both the real and imaginary modes. Shear flow also leads to an increase in the fraction of modes with imaginary frequencies. The implications of these changes are discussed in regard to other system properties.