Transport in 2D Complex Plasma Crystals

Abstract

In this chapter, we investigate numerically the transport properties of a 2D complex plasma crystal by examining the propagation of coplanar dust lattice waves. In the limit where the Hamiltonian interactions can be decoupled from the non-Hamiltonian effects, we identify two distinct regimes of wave transport: Anderson-type delocalization and long-distance excitation. We use the spectral approach to evaluate the contribution from the Anderson problem, i.e. to determine whether the initial lattice perturbation delocalized through nearest neighbor (short distance) interaction. The theoretical predictions are then compared against the results from a mulecular dynamics simulation. Any major deviations between the predicted and observed crystal dynamics are contributed to non-Hamiltonian effects. The benefit of our approach is twofold. First, the use of complex plasma system allows for tunability of the initial conditions and investigation of the transport problem at the kinetic level. In addition, the 2D dust crystal exhibit hexagonal symmetry, which makes it an ideal macroscopic analogue for materials, such as graphene. Second, the Hamiltonian part of the transport problem is analyzed using a theoretical approach, which determines delocalization in an infinite disordered system without the use of finite-size scaling or periodic boundary conditions. Thus, the comparison between theoretical and numerical results can be used to evaluate the effect of the actual physical boundaries and system size.