Regensburg 2010 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 4: CE: Quantum Impurities, Kondo Physics
TT 4.7: Talk
Monday, March 22, 2010, 12:00–12:15, H21
Relaxation vs decoherence: Spin and current dynamics in the anisotropic Kondo model at finite bias and magnetic field — •Mikhail Pletyukhov, Dirk Schuricht, and Herbert Schoeller — Institut für theoretische Physik A, RWTH Aachen, Germany
Using a nonequilibrium renormalization group method we study the real-time evolution of spin and current in the anisotropic Kondo model (both antiferromagnetic and ferromagnetic) at finite magnetic field h0 and bias voltage V. We derive analytic expressions for all times in the weak-coupling regime max{V,h0,1/t}≫ Tc (Tc= strong coupling scale). We find that all observables decay both with the spin relaxation and decoherence rates Γ1/2. Various V-dependent logarithmic, oscillatory, and power-law contributions are predicted. The low-energy cutoff of logarithmic terms is generically identified by the difference of transport decay rates. For small times t≪ max{V,h0}−1, we obtain universal dynamics for spin and current.