Fano resonances and electron spin transport through a two-dimensional spin-orbit-coupled quantum ring

TL;DR

This paper investigates how finite-width effects and spin-orbit interaction in a quantum ring lead to Fano resonances in conductance and significantly influence spin transport, especially near Aharonov-Casher oscillation maxima.

Contribution

It demonstrates the emergence of Fano resonances due to finite width and spin-orbit coupling, revealing their impact on spin transport beyond one-dimensional models.

Findings

Fano resonances appear in conductance due to finite width and spin-orbit interaction.

Resonances are prominent near maxima of Aharonov-Casher oscillations.

Spin transport depends on electron Fermi energy when detuned from maxima.

Abstract

Electron transport through a spin-orbit-coupled quantum ring is investigated within linear response theory. We show that the finite width of the ring results in the appearance of Fano resonances in the conductance. This turns out to be a consequence of the spin-orbit interaction that leads to a breaking of the parity of the states localized in the ring. The resonances appear when the system is close to maxima of Aharonov-Casher conductance oscillations where spin transfer is heavily modified. When the spin-orbit coupling strength is detuned from the Aharonov-Casher maxima the resonances are broadened resulting in a dependence of the spin transport on the electron Fermi energy in contrast to predictions from one-dimensional models