Magnetic field effects on electron transport in nanoring with orbital Rashba coupling

TL;DR

This paper investigates how a Zeeman magnetic field influences electron transport in one-dimensional quantum rings with orbital Rashba coupling, revealing effects on the Aharonov-Anandan phase and channel selectivity.

Contribution

It provides a detailed analysis of magnetic field effects on electron transport and phase behavior in quantum rings with orbital Rashba coupling, highlighting channel selection and interference phenomena.

Findings

Magnetic field can select a single transport channel affected by the AA phase.

Oscillations in transmission occur due to dynamical contributions when multiple channels are involved.

Transmission becomes chiral near the minimum of energy bands and saturates at high magnetic fields.

Abstract

We study the effects of a Zeeman magnetic field on the electron transport of one-dimensional quantum rings which are marked by electronic states with $d-$orbital symmetry in the presence of spin-orbit and orbital Rashba couplings. By considering phase-coherent propagation, we analyse the geometric Aharonov-Anandan (AA) phase of the channels which is acquired in a closed path, by demonstrating that the orbital polarization can influence the electronic transport when amplitude and magnetic field directions are varied. We explore all the possible cases for the injection of electrons at various energies in the regime of low electron filling. The magnetic field can allow the selection of only one channel where the transmission is uniquely affected by the AA phase. Conversely, when more orbital channels are involved there is also a dynamical contribution that lead to oscillations in the transmission as the magnetic field is varied. In particular, the transmission is chiral when the energy states are close to the absolute minimum of the energy bands. Instead, when an interference between the channels occurs the orbital and spin contributions tend to balance each other with the increasing of the magnetic field amplitude resulting in a trivial AA phase. This saturation effect does not occur in the high magnetic field regime when orbital and spin properties of the channels exhibit sharp variations with direct consequences on the transport.