Anomalous multifractality in quantum chains with strongly correlated disorder
Alexander Duthie, Sthitadhi Roy, David E. Logan
Abstract
We demonstrate numerically that a robust and unusual multifractal regime can emerge in a one-dimensional quantum chain with maximally correlated disorder, above a threshold disorder strength. This regime is preceded by a mixed and an extended regime at weaker disorder strengths, with the former hosting both extended and multifractal eigenstates. The multifractal states we find are markedly different from conventional multifractal states in their structure, as they reside approximately uniformly over a continuous segment of the chain, and the lengths of these segments scale nontrivially with system size. This anomalous nature also leaves imprints on dynamics. An initially localized wave packet shows ballistic transport, in contrast to the slow, generally subdiffusive, transport commonly associated with multifractality. However, the timescale over which this ballistic transport persists again scales nontrivially with the system size.