Coupling in concentric double quantum rings

Abstract

We designed a device consisting of two concentric quantum rings in a GaAsAlGaAs heterostructure. The outer ring is connected to leads while the inner ring is only capacitively coupled to the rest of the system. Measuring electronic transport in a regime with strong coupling to the leads we found that the conductivity not only shows an Aharonov-Bohm effect with a periodicity fitting to the diameter of the outer ring but also another component matching the inner ring. This can be explained by magnetic-field dependent charge redistributions in the inner ring which affect the outer ring via Coulomb interaction. © 2007 American Institute of Physics.