Electron localizations in double concentric quantum ring

TL;DR

This paper studies how electrons localize and transition between two concentric quantum rings under a magnetic field, revealing that level anti-crossings enable electron tunneling between the rings.

Contribution

It demonstrates the role of energy level anti-crossings in electron tunneling within double concentric quantum rings, using numerical simulations based on an effective mass approach.

Findings

Electron transitions occur due to level anti-crossings.

Anti-crossings enable electron tunneling between rings.

Numerical results align with experimental geometries.

Abstract

We investigate the electron localization in double concentric quantum rings (DCQRs) when a perpendicular magnetic field is applied. In weakly coupled DCQRs, the situation can occur when the single electron energy levels associated with different rings may be crossed. To avoid degeneracy, the anti-crossing of these levels has a place. We show that in this DCQR the electron spatial transition between the rings occurs due to the electron level anti-crossing. The anti-crossing of the levels with different radial quantum numbers provides the conditions for electron tunneling between rings. To study electronic structure of the semiconductor DCQR, the single sub-band effective mass approach with energy dependence was used. Results of numerical simulation for the electron transition are presented for DCQRs of geometry related to one fabricated in experiment.