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Journal of Statistical Physics
We investigate the relaxation mechanism of a supercooled tetrahedral liquid at its limit of stabi... more We investigate the relaxation mechanism of a supercooled tetrahedral liquid at its limit of stability using isothermal isobaric (N P T) Monte Carlo (MC) simulations. In similarity with systems which are far from equilibrium but near the onset of jamming [O'Hern et.al., Phys. Rev. Lett. 93, 165702 (2004)], we find that the relaxation is characterized by two timescales: the decay of longwavelength (slow) fluctuations of potential energy is controlled by the slope [∂(G/N)/∂φ] of the Gibbs free energy (G) at a unique value of per particle potential energy φ = φ mid. The short-wavelength (fast) fluctuations are controlled by the bath temperature T. The relaxation of the supercooled liquid is initiated with a dynamical crossover after which the potential energy fluctuations are biased towards values progressively lesser than φ mid. The dynamical crossover leads to the change of timescale , i.e., the decay of long-wavelength potential energy fluctuations (intermediate stage of relaxation). Because of the condition [∂ 2 (G/N)/∂φ 2 = 0] at φ = φ mid , the slope [∂(G/N)/∂φ] has a unique value and governs the intermediate stage of relaxation, which ends just after the crossover. In the subsequent stage, there is a relatively rapid crystallization due to lack of long-wavelength fluctuations and the instability at φ mid , i.e., the condition that G decreases as configurations with potential energies lower than φ mid are accessed. The dynamical crossover point and the associated change in the timescale of fluctuations is found to be consistent with the previous studies.
Journal of Statistical Physics
We investigate the relaxation mechanism of a supercooled tetrahedral liquid at its limit of stabi... more We investigate the relaxation mechanism of a supercooled tetrahedral liquid at its limit of stability using isothermal isobaric (N P T) Monte Carlo (MC) simulations. In similarity with systems which are far from equilibrium but near the onset of jamming [O'Hern et.al., Phys. Rev. Lett. 93, 165702 (2004)], we find that the relaxation is characterized by two timescales: the decay of longwavelength (slow) fluctuations of potential energy is controlled by the slope [∂(G/N)/∂φ] of the Gibbs free energy (G) at a unique value of per particle potential energy φ = φ mid. The short-wavelength (fast) fluctuations are controlled by the bath temperature T. The relaxation of the supercooled liquid is initiated with a dynamical crossover after which the potential energy fluctuations are biased towards values progressively lesser than φ mid. The dynamical crossover leads to the change of timescale , i.e., the decay of long-wavelength potential energy fluctuations (intermediate stage of relaxation). Because of the condition [∂ 2 (G/N)/∂φ 2 = 0] at φ = φ mid , the slope [∂(G/N)/∂φ] has a unique value and governs the intermediate stage of relaxation, which ends just after the crossover. In the subsequent stage, there is a relatively rapid crystallization due to lack of long-wavelength fluctuations and the instability at φ mid , i.e., the condition that G decreases as configurations with potential energies lower than φ mid are accessed. The dynamical crossover point and the associated change in the timescale of fluctuations is found to be consistent with the previous studies.