Dynamic Response of Isolated Aharonov-Bohm Rings Coupled to an Electromagnetic Resonator

Abstract

We have measured the flux dependence of both the real and the imaginary conductance of $\mathrm{GaAs}/\mathrm{GaAlAs}$ isolated mesoscopic rings at 310 MHz. The rings are coupled to a highly sensitive electromagnetic superconducting microresonator and lead to a perturbation of the resonance frequency and quality factor. This experiment provides a new tool for the investigation of the conductance of mesoscopic systems without the need for invasive probes. The results obtained can be compared with recent theoretical predictions emphasizing the differences between isolated and connected geometries and the relation between ac conductance and persistent currents.