Optical exciton Aharonov-Bohm effect, persistent current, and magnetization in semiconductor nanorings of type I and II

TL;DR

This paper investigates the optical exciton Aharonov-Bohm effect in semiconductor nanorings, demonstrating conditions for observation and linking theoretical models, while also analyzing magnetization and persistent currents to reveal topological properties.

Contribution

It provides a detailed analysis of the optical exciton Aharonov-Bohm effect in nanorings, establishing conditions for observation and connecting different theoretical approaches.

Findings

Optimal conditions for observing the effect identified

A method to extract Aharonov-Bohm oscillations unambiguously

Magnetization and persistent current oscillate with magnetic field

Abstract

The optical exciton Aharonov-Bohm effect, i. e. an oscillatory component in the energy of optically active (bright) states, is investigated in nanorings. It is shown that a small effective electron mass, strong confinement of the electron, and high barrier for the hole, achieved e. g. by an InAs nanoring embedded in an AlGaSb quantum well, are favorable for observing the optical exciton Aharonov-Bohm effect. The second derivative of the exciton energy with respect to the magnetic field is utilized to extract Aharonov-Bohm oscillations even for the lowest bright state unambiguously. A connection between the theories for infinitesimal narrow and finite width rings is established. Furthermore, the magnetization is compared to the persistent current, which oscillates periodically with the magnetic field and confirms thus the non-trivial (connected) topology of the wave function in the nanoring.