Berlin 2012 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 18: Correlated Electrons: Quantum Impurities, Kondo Physics 2

TT 18.5: Vortrag

Dienstag, 27. März 2012, 10:30–10:45, H 3005

Non-equilibrium transport through a multichannel Kondo dot at finite magnetic field — •Christoph B. M. Hörig and Dirk Schuricht — RWTH Aachen, Germany

Motivated by a recent work [1] on non-equilibrium transport through a multichannel Kondo model, we study a spin-1/2 quantum dot in a finite magnetic field using the real-time renormalization group (RG) method [2].

The quantum dot is coupled to K independent reservoirs via spin exchange interaction, which leads to the overscreened Kondo effect. Based on a systematic expansion in the exchange coupling we integrate out the reservoir degrees of freedom and solve the resulting two-loop RG equations in the weak-coupling regime K>>1. We derive the scaling functions of the coupling constants towards the K-channel fix point and investigate the influence of decoherence during this flow.

Furthermore, we determine the effect of channel-dependent bias voltages on the magnetization and the differential conductance via inelastic cotunneling processes, and discuss our results in the context of previous experiments [3].
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H. Schoeller and F. Reininghaus, Phys. Rev. B 80, 045117 (2009).
R. M. Potok et al., Nature 446, 167 (2007).