Electron transfer through a multiterminal quantum ring: magnetic forces and elastic scattering effects

TL;DR

This paper investigates how an elastic scatterer within a quantum ring affects electron transport, conductance oscillations, and magnetic symmetry, aligning theoretical insights with recent experimental observations.

Contribution

It provides a theoretical analysis of elastic scattering effects on electron transport and conductance symmetry in a multiterminal quantum ring, explaining experimental findings.

Findings

Scatterer causes asymmetry in output transport probabilities.

Elastic scattering reduces Aharonov-Bohm oscillation visibility.

Magnetic symmetry of conductance sum explained by backscattering invariance.

Abstract

We study electron transport through a semiconductor quantum ring with one input and two output terminals for an elastic scatterer present within one of the arms of the ring. We demonstrate that the scatterer not only introduces asymmetry in the transport probability to the two output leads but also reduces the visibility of the Aharonov-Bohm conductance oscillations. This reduction occurs in spite of the phase coherence of the elastic scattering and is due to interruption of the electron circulation around the ring by the potential defect. The results are in a qualitative agreement with a recent experiment by Strambini et al. [Phys. Rev. B {\bf 79}, 195443 (2009)]. We also indicate that the magnetic symmetry of the sum of conductance of both the output leads as obtained in the experiment can be understood as resulting from the invariance of backscattering to the input lead with respect to the magnetic field orientation.