Current-spin-density-functional study of persistent currents in quantum rings

We present a numerical study of persistent currents in quantum rings using current-spin-density-functional theory (CSDFT). This formalism allows for a systematic study of the joint effects of spin, interactions and impurities for realistic systems. It is illustrated that CSDFT is suitable for descri bing the physical effects related to Aharonov-Bohm phases by comparing ener gy spectra of impurity-free rings to existing exact diagonalization and exp erimental results. Further, we examine the effects of a symmetry-breaking i mpurity potential on the density and current characteristics of the system and propose that narrowing the confining potential at fixed impurity potent ial will suppress the persistent current in a characteristic way.