Controlled electron transport in coupled Aharonov-Bohm rings

TL;DR

This paper presents a model of coupled Aharonov-Bohm rings that enables controlled, ballistic electron transmission by tuning magnetic flux, revealing phenomena like Fano resonances and suppression of Aharonov-Bohm oscillations.

Contribution

It provides an exact analytical framework for controlling electron transport in coupled rings through magnetic flux tuning, highlighting novel resonance behaviors.

Findings

Ballistic transmission can be precisely controlled by flux tuning.

Fano resonances appear and collapse under certain conditions.

Aharonov-Bohm oscillations can be suppressed in the system.

Abstract

We propose a simple model of two coupled mesoscopic rings threaded by magnetic flux which mimics a device for electron transmission in a controlled fashion. Within a tight binding formalism we work out exactly the conditions when a completely ballistic transmission can be triggered at any desired position of the Fermi level within a continuous range of energy. The switching action can be easily controlled by appropriately tuning the values of the flux through the two rings. The general transmission across the ring system displays interesting features characterized by the appearance and collapse of Fano resonances, and the suppression of the Aharonov-Bohm oscillations in several cases. We report and analyze exact analytical results for a few such cases.