The Jamming Transition and the Marginally Jammed Solid

When a system jams, it undergoes a transition from a flowing to a rigid state. Despite this important change in the dynamics, the internal structure of the system remains disordered in the solid as well as the fluid phase. In this way jamming is quite different from crystallization, the other common way in which a fluid solidifies. Jamming is a paradigm for thinking about how many different types of fluids—from molecular liquids to macroscopic granular matter—develop rigidity. Here we review recent work on the jamming transition. We start with perhaps the simplest model: frictionless spheres interacting via repulsive finite-range forces at zero temperature. In this highly idealized case, the transition has…