Compact, flat-band based, Anderson and many-body localization in a diamond chain

Nilanjan Roy, Ajith Ramachandran, Auditya Sharma

Published 2019-12-20Version 1

The interplay of dispersionless bands, compact localized eigenstates, disorder and interactions, in a quasi one-dimensional diamond chain results in a rich phase diagram. Localization properties of the system vary from extreme compact localization in the dispersionless limit to weak flat-band based localization in the presence of tiny disorder, to the familiar strong Anderson localization in the presence of large disorder. Furthermore, when interactions are turned on, the many-body localized phase is also realized in some parameter regimes. The phase diagram is chalked out on the basis of both single-particle properties including inverse participation ratio, return probability, wave-packet dynamics, and many-particle properties including level spacing ratio, many-particle inverse participation ratio, return probability, and imbalance parameter.