Kondo quantum dot coupled to ferromagnetic leads: Numerical renormalization group study

Details Kondo quantum dot coupled to ferromagnetic leads: Numerical renormalization group study Kondo quantum dot coupled to ferromagnetic leads: Numerical renormalization group study

2007-06-27

arxiv.org/abs/0706.3997v1

Phys. Rev. B 76, 045321 (2007)

Physics

Condensed Matter

Mesoscale and Nanoscale Physics

18 pages, 18 figures, accepted for publication in PRB

Scientific paper

10.1103/PhysRevB.76.045321

We systematically study the influence of ferromagnetic leads on the Kondo resonance in a quantum dot tuned to the local moment regime. We employ Wilson's numerical renormalization group method, extended to handle leads with a spin asymmetric density of states, to identify the effects of (i) a finite spin polarization in the leads (at the Fermi-surface), (ii) a Stoner splitting in the bands (governed by the band edges) and (iii) an arbitrary shape of the leads density of states. For a generic lead density of states the quantum dot favors being occupied by a particular spin-species due to exchange interaction with ferromagnetic leads leading to a suppression and splitting of the Kondo resonance. The application of a magnetic field can compensate this asymmetry restoring the Kondo effect. We study both the gate-voltage dependence (for a fixed band structure in the leads) and the spin polarization dependence (for fixed gate voltage) of this compensation field for various types of bands. Interestingly, we find that the full recovery of the Kondo resonance of a quantum dot in presence of leads with an energy dependent density of states is not only possible by an appropriately tuned external magnetic field but also via an appropriately tuned gate voltage. For flat bands simple formulas for the splitting of the local level as a function of the spin polarization and gate voltage are given.

Affiliated with

Also associated with

No associations

Rating

Kondo quantum dot coupled to ferromagnetic leads: Numerical renormalization group study does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Kondo quantum dot coupled to ferromagnetic leads: Numerical renormalization group study, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Kondo quantum dot coupled to ferromagnetic leads: Numerical renormalization group study will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-255802