CONDITIONS FOR THE EXISTENCE OF A REENTRANT SOLID-PHASE IN A SHEARED ATOMIC FLUID

A nonequilibrium molecular-dynamics method is proposed to simulate the behavior of simple fluids under high shear rates. A thermostat that makes no assumptions regarding the form of the streaming velocity of the fluid is introduced. Simulations are carried out for a Weeks-Chandler-Andersen dense liquid. With the form of the streaming velocity partially or wholly constrained, we find evidence for a reentrant solid or string phase, but the phase disappears if constraints are removed. Small-angle neutron-scattering data from a sheared colloidal suspension are presented. There is no evidence of a steady-state shear-induced structure in the suspension.