Aharonov-Bohm oscillations in a mesoscopic ring with a quantum dot

TL;DR

This paper analyzes Aharonov-Bohm oscillations in a mesoscopic ring with a quantum dot, revealing abrupt phase changes at resonance crossings and discussing parity conservation using the Friedel sum rule.

Contribution

It introduces a theoretical analysis of phase behavior in Aharonov-Bohm oscillations with a quantum dot, highlighting the impact of resonant level crossings.

Findings

Phase of oscillations changes abruptly at resonance crossing

Parity of oscillations remains conserved at conductance peaks

Model demonstrates potential landscape effects on oscillations

Abstract

We present an analysis of the Aharonov-Bohm oscillations for a mesoscopic ring with a quantum dot inserted in one of its arms. It is shown that microreversibility demands that the phase of the Aharonov-Bohm oscillations changes {\it abruptly} when a resonant level crosses the Fermi energy. We use the Friedel sum rule to discuss the conservation of the parity of the oscillations at different conductance peaks. Our predictions are illustrated with the help of a simple one channel model that permits the variation of the potential landscape along the ring.