Aging, yielding, and shear banding in soft colloidal glasses

Soft colloidal interactions in colloidal glasses are modeled using suspensions of multiarm star polymers. Using a preshearing protocol that ensures a reproducible initial state (rejuvenation of the system), we report here the evolution of the flow curve from monotonically increasing to one dominated by a stress plateau, demonstrating a corresponding shear-banded state. Phenomenological understanding is provided through a scalar model that describes the free-energy landscape.