  We investigate the electron localization in double concentric quantum rings
(DCQRs) when a perpendicular magnetic field is applied. In weakly coupled
DCQRs, the situation can occur when the single electron energy levels
associated with different rings may be crossed. To avoid degeneracy, the
anti-crossing of these levels has a place. We show that in this DCQR the
electron spatial transition between the rings occurs due to the electron level
anti-crossing. The anti-crossing of the levels with different radial quantum
numbers provides the conditions for electron tunneling between rings. To study
electronic structure of the semiconductor DCQR, the single sub-band effective
mass approach with energy dependence was used. Results of numerical simulation
for the electron transition are presented for DCQRs of geometry related to one
fabricated in experiment.
