Kondo effect in spin-orbit mesoscopic interferometers

Abstract

We consider a flux-threaded Aharonov-Bohm ring with an embedded quantum dot coupled to two normal leads. The local Rashba spin-orbit interaction acting on the dot electrons leads to a spin-dependent phase factor in addition to the Aharonov-Bohm phase caused by the external flux. Using the numerical renormalization group method, we find a splitting of the Kondo resonance at the Fermi level which can be compensated by an external magnetic field. To fully understand the nature of this compensation effect, we perform a scaling analysis and derive an expression for the effective magnetic field. The analysis is based on a tight-binding model which leads to an effective Anderson model with a spin-dependent density of states for the transformed lead states. We find that the effective field originates from the combined effect of Rashba interaction and magnetic flux and that it contains important corrections due to electron-electron interactions. We show that the compensating field is an oscillatory function of both the spin-orbit and the Aharonov-Bohm phases. Moreover, the effective field never vanishes due to the particle-hole symmetry breaking independently of the gate voltage.

9 pages, 5 figures

References in corpus (13)

• Sum-rule Conserving Spectral Functions from the Numerical Renormalization Group
• Kondo effect in quantum dots coupled to ferromagnetic leads
• Quantum transport theory for nanostructures with Rashba spin-orbital interaction
• A Numerical Renormalization Group approach to Green's Functions for Quantum Impurity Models
• NRG study of the Kondo effect in the presence of itinerant-electron ferromagnetism
• Bias-controllable intrinsic spin polarization in a quantum dot
• Magnetic field dependent transmission phase of a double dot system in a quantum ring
• Aharonov-Bohm oscillations in the presence of strong spin-orbit interactions
• From Coulomb blockade to the Kondo regime in a Rashba dot
• Spin-charge filtering through a spin-orbit coupled quantum dot controlled via an Aharonov-Bohm interferometer
• Kondo screening suppression by spin-orbit interaction in quantum dots
• Localized magnetic states in Rashba dots
• Compensation of the Kondo effect in quantum dots coupled to ferromagnetic leads within equation of motion approach

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• Nanoscopic interferometer model for spin resonance in current noise
• Phase-controlled heat modulation with Aharonov-Bohm interferometers