From Coulomb blockade to the Kondo regime in a Rashba dot

TL;DR

This paper explores how localized Rashba interactions in a quantum wire create quasi-bound states that influence electronic transport, leading to Fano resonances, Coulomb blockade, and tunable Kondo effects.

Contribution

It demonstrates the emergence of Coulomb blockade and Kondo regimes in a Rashba dot, revealing new ways to control quantum transport via spin-orbit coupling.

Findings

Fano-like antiresonances in conductance due to Rashba dot

Large charging energies induce Coulomb blockade effects

Kondo regime achievable through Rashba interaction tuning

Abstract

We investigate the electronic transport in a quantum wire with localized Rashba interaction. The Rashba field forms quasi-bound states which couple to the continuum states with an opposite spin direction. The presence of this Rashba dot causes Fano-like antiresonances and dips in the wire's linear conductance. The Fano lineshape arises from the interference between the direct transmission channel along the wire and the hopping through the Rashba dot. Due to the confinement, we predict the observation of large charging energies in the local Rashba region which lead to Coulomb-blockade effects in the transport properties of the wire. Importantly, the Kondo regime can be achieved with a proper tuning of the Rashba interaction, giving rise to an oscillating linear conductance for a fixed occupation of the Rashba dot.