Athermal Jamming vs Thermalized Glassiness in Sheared Frictionless Particles

Numerical simulations of soft-core frictionless disks in two dimensions are carried out to study behavior of a simple liquid as a function of thermal temperature $T$, packing fraction $\varphi$, and uniform applied shear strain rate $\dot{\gamma }$. Inferring the hard-core limit from our soft-core results, we find that it depends on the two parameters $\varphi$ and $T\mathrm{/}\dot{\gamma }$. $T\mathrm{/}\dot{\gamma }\to 0$ defines the athermal limit in which a shear driven jamming transition occurs at a well defined ${\varphi }_J$. $T\mathrm{/}\dot{\gamma }\to \mathrm{\infty }$ defines the thermalized limit where an equilibrium glass transition may take place at a ${\varphi }_G$. This conclusion argues that athermal jamming and equilibrium glassy behavior are not controlled by the same critical point. Preliminary results suggest ${\varphi }_G<{\varphi }_J$.