The generic fixed point model for pseudo-spin-1/2 quantum dots in nonequilibrium: Spin-valve systems with compensating spin polarizations

Abstract

We study a pseudo-spin-1/2 quantum dot in the cotunneling regime close to the particle-hole symmetric point. For a generic tunneling matrix we find a generic fixed point with interesting nonequilibrium properties, characterized by effective reservoirs with compensating spin orientation vectors weighted by the polarizations and the tunneling rates. At large bias voltage we study the magnetic field dependence of the dot magnetization and the current. The fixed point can be clearly identified by analyzing the magnetization of the dot. We characterize in detail the universal properties for the case of two reservoirs.

References in corpus (9)

• Kondo effect in quantum dots coupled to ferromagnetic leads
• NRG study of the Kondo effect in the presence of itinerant-electron ferromagnetism
• A perturbative nonequilibrium renormalization group method for dissipative quantum mechanics: Real-time RG in frequency space (RTRG-FS)
• Charge transport through single molecules, quantum dots, and quantum wires
• Unified description of correlations in double quantum dots
• Real-time renormalization group in frequency space: A 2-loop analysis of the nonequilibrium anisotropic Kondo model at finite magnetic field
• Real-time renormalization group and cutoff scales in nonequilibrium applied to an arbitrary quantum dot in the Coulomb blockade regime
• Kondo model in nonequilibrium: Interplay between voltage, temperature, and crossover from weak to strong coupling
• Keldysh effective action theory for universal physics in spin-1/2 Kondo dots