Persistent current in a one-dimensional correlated disordered ring

Persistent currents and charge stiffness in one-dimensional (1D) correlated disordered rings are investigated by a transfer-matrix method. It is found that, under certain conditions the electronic states do not feel the existence of the disorder and the ring recovers the ordered case. If the occupied energy is just at the unscattered state energy level, the persistent current is not reduced and shows the behavior of sudden jumps regardless of the disorder, contrary to the general theorem where the current is obviously reduced and becomes a smooth function of flux, passing through zero. For other occupied energy, the persistent current is scattered and decreased as expected. The results indicate that a quantum interference effect can be observed in 1D correlated disordered rings. Further, the results provide evidence that the realization of delocalized states in the experiments is easily obtained by observing only the persistent current of finite length rings, in contrast to the 1D disordered chain where the infinite length is needed.