Collective Dynamics in Quasi-One-Dimensional Hard Disk System

We present the results of molecular dynamic studies of collective dynamics in a system of hard disks confined to a narrow quasi-one-dimensional (quasi-1D) channel. The computer simulations have been performed for the specific channel width of 3/2 of disk diameter in which the disk arrangement at close packing resembles zigzag ordering characteristic of a vertically oriented two-dimensional (2D) triangular lattice. In such a quasi-1D system, which is intermediate between 1D and 2D arrays of hard disks, the transverse excitations obey very specific dispersion law typical of the usual optical transverse modes. This is in a sharp contrast both to the 1D case, where transverse excitations are not possible, and to the 2D case, where the regular shear waves with a propagation gap were observed. Other peculiarities of the dispersion of collective excitations as well as some results of disk structuring and thermodynamics of the quasi-1D hard disk system are presented and discussed for a range of hard disk densities typical for fluid and distorted crystal states.

Automated summary

The study presents results of molecular dynamic studies on the collective dynamics in a system of hard disks confined to a narrow quasi-one-dimensional channel. It shows that in such a quasi-1D system, transverse excitations follow specific dispersion law typical of optical transverse modes, contrasting sharply to the cases of 1D and 2D arrays of hard disks. Other peculiarities of the dispersion of collective excitations as well as some results of disk structuring and thermodynamics of the system are also discussed.