Topological effects on magnitude of persistent current in a ring

Abstract

We show that defects in 1D rings decrease the conductance (when the ring is opened up) many more times than it decreases the persistent currents. This means that the states in such a 1D ring are very sensitive to twisting of boundary condition but conductance of the system is small. In 1D the electron effectively sees a periodic potential and escapes localization. This does not happen in higher dimensions. This helps us to understand the simulations of G. Kirczenow[13] and also suggests that a rough boundary in a 3D ring that provide effectively a strong 1D potential to the electron will have this type of different effects on conductance and persistent currents.