Bias-induced circular current in a loop nanojunction with AAH modulation: Role of hopping dimerization

Abstract

In this work, we investigate the interplay between correlated disorder and hopping dimerization on bias-driven circular current in a loop conductor that is clamped between two electrodes. The correlated disorder is introduced in site energies of the ring in the form of Aubry-André-Harper (AAH) model. Simulating the quantum system within a tight-binding framework all the results are worked out based on the waveguide theory. Unlike transport current, circular current in the loop conductor can get enhanced with increasing disorder strength. This enhancement becomes much effective when hopping dimerization is included which is taken following the Su-Schrieffer-Heeger (SSH) model. The characteristic features of bias-driven circular current are studied under different input conditions and we find that the results are robust for a wide range of physical parameters. For the sake of completeness, uncorrelated disorder is also considered. Our analysis may provide a new insight in analyzing transport behavior in different disordered lattices in the presence of additional restrictions in hopping integrals.