Nonequilibrium Dynamics in Amorphous Si_3b_3n_7

摘要

We present extensive numerical investigations of the structural relaxation dynamics of a realistic model of the amorphous high-temperature ceramic alpha-Si_3b_3n_7,probing the mean-square displacement of the atoms,the bond survival probability,the average energy,the specific heat,and the two-point energy average.Combining the information from these different sources,we identify a transition temperature T_c approx= 2000 K below which the system is no longer ergodic and physical quantities observed over a time t_(obs)show a systematic parametric dependence on the waiting time t_w,or age,elapsed after the quench.The aging dynamics "stiffens" as the system becomes older,which is similar to the behavior of highly idealized models such as Ising spin glasses and Lennard-Jones glasses.