IS THE MAGNETIC-FIELD NECESSARY FOR THE AHARONOV-BOHM EFFECT IN MESOSCOPICS

We predict a new class of topological mesoscopic phenomena in absence of external magnetic field, based on combined action of the nonequilib rium nuclear spin population and charge carrier spin-orbit interaction . We show that Aharonov-Bohm-like oscillations of the persistent curre nt in GaAs/AlGaAs based mesoscopic rings may exist in the absence of t he external magnetic field, provided that a topologically nontrivial s trongly nonequilibrium nuclear spin population is created. This phenom enon is due to the breaking, via the spin-orbit coupling, of the clock wise-anticlockwise symmetry of the charge carriers momentum, which res ults in an oscillatory in time persistent current.