2012/02/15 by Tian, Chushun
#Disordered Systems and Neural Networks (cond-mat.dis-nn) #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
paper · doi:10.48550/arxiv.1202.3187
We develop a non-perturbative theory to study large-scale quantum dynamics of Dirac particles in disordered scalar potentials (the so-called "topological metal"). For general disorder strength and carrier doping, we find that at large times, superdiffusion occurs. I.e., the mean squared displacement grows as ∼ tln t. In the static limit, our analytical theory shows that the conductance of a finite-size system obeys the scaling equation identical to that found in previous numerical studies. These results suggest that in the topological metal, there exist some transparent channels -- where waves propagate "freely" -- dominating long-time transport of the system. We discuss the ensuing consequence -- the transverse superdiffusion in photonic materials -- that might be within the current experimental reach.