Phys Rev E Stat Nonlin Soft Matter Phys. 2013 Oct;88(4):043103. doi: 10.1103/PhysRevE.88.043103. Epub 2013 Oct 16.

Mode couplings and resonance instabilities in dust clusters.

Physical review. E, Statistical, nonlinear, and soft matter physics

Ke Qiao, Jie Kong, Eric Van Oeveren, Lorin S Matthews, Truell W Hyde

PMID: 24229289 DOI: 10.1103/PhysRevE.88.043103

Abstract

The normal modes for three to seven particle two-dimensional (2D) dust clusters in a complex plasma are investigated using an N-body simulation. The ion wakefield downstream of each particle is shown to induce coupling between horizontal and vertical modes. The rules of mode coupling are investigated by classifying the mode eigenvectors employing the Bessel and trigonometric functions indexed by order integers (m, n). It is shown that coupling only occurs between two modes with the same m and that horizontal modes having a higher shear contribution exhibit weaker coupling. Three types of resonances are shown to occur when two coupled modes have the same frequency. Discrete instabilities caused by both the first and third type of resonances are verified and instabilities caused by the third type of resonance are found to induce melting. The melting procedure is observed to go through a two-step process with the solid-liquid transition closely obeying the Lindemann criterion.

Publication Types

• Journal Article
• Research Support, U.S. Gov't, Non-P.H.S.