Research Assistant, PhD candidate, Baylor University


A numerical study of the Anderson localization in a 2D complex plasma crystal

In condensed matter, a crystal without impurities at zero temperature acts like a perfect conductor for a travelling electron. As the amount of lattice disorder reaches a critical value, the electron wavefunction experiences a transition from extended to a localized state, called Anderson localization. The existence of such transition in 2D materials has been the subject of heated debate over the past few decades due to a disagreement between theoretical prediction and experimental observation. Here, we present a numerical study of the Anderson localization in a 2D complex plasma crystal, which is used as a macroscopic analogue of a disordered 2D material. The goal of this research is to establish if Anderson localization can be experimentally observed in a 2D complex plasma crystal and to determine how spatial defects influence the dynamical behavior of strongly coupled Coulomb systems.
Complex plasma crystals exhibit characteristic distance and time scales which are easily observable by video microscopy. As such, these strongly coupled many-particle systems are ideal for the study of localization phenomena in the classical regime. In this work, we investigate the transport properties of the dusty plasma crystal by analyzing the diffusion of coplanar lattice waves travelling within the medium. The results from our simulations are compared to the predictions of a novel mathematical method, called the spectral approach to delocalization. The spectral approach determines (with probability 1) the existence of extended states in infinite disordered lattices of any dimension without the use of boundary conditions or scaling. Thus, the comparison between theoretical and numerical results is used to evaluate the effect of physical boundaries and system size. We further discuss the interplay between disorder-driven behavior and interparticle interaction in the strongly coupled dusty plasma system.