STUDY ON THE BETA-PEAK OF CHI'' FOR A 2-DIMENSIONAL SUPERCOOLED FLUIDSTATE VIA MOLECULAR-DYNAMICS SIMULATION

We have computed the generalized susceptibility (imaginary part of chi ) of two-dimensional supercooled fluid states through molecular dynami cs simulations with different system sizes. It is found that when the temperature of the system is higher than T-c (critical temperature) th ere is no significant difference between the large (10,000-particle) a nd small (100-particle) systems in the chi'' obtained, but for much lo wer temperatures the spectra of the chi'' obtained reveal a remarkable system-size dependent behavior such as the beta peak becomes much bro ader for the large system. This phenomenon is physically understood in terms of the strongly correlated motion of atoms extending over a wid e range of space of the system. We will discuss in this work about the relaxations on two-dimensional supercooled fluids and their microscop ic origins as well as their system-size dependence.