Measuring configurational entropy of glasses using population annealing

In this talk we present two methods to calculate the vibrational (S_vib) and configurational (S_c) entropies of glassy fluids in the context of population annealing Monte Carlo. The first method for obtaining S_vib integrates the pressure of individual configurations from the fluid phase to the glass phase, and the second method introduces a hard shell constraining potential to individual particles at fixed packing fraction in the glassy regime and integrates the entropy to the highly constrained, ideal gas limit. Using population annealing, we obtain measurements of S_vib and S_c at high densities for fluids with 30, 60, and 100 particles and compare the two methods. Our results show that the two methods agree and that even for modest-sized systems, finite-size effects on S_c appear to be small.