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arXiv · 1204.5418

Relaxation dynamics of the Kondo lattice model

Philipp Werner·Martin Eckstein
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Abstract

We study the relaxation properties of the Kondo lattice model using the nonequilibrium dynamical mean field formalism in combination with the non-crossing approximation. The system is driven out of equilibrium either by a magnetic field pulse which perturbs the local singlets, or by a sudden quench of the Kondo coupling. For relaxation processes close to thermal equilibrium (after a weak perturbation), the relaxation time increases substantially as one crosses from the local moment regime into the heavy Fermi liquid. A strong perturbation, which injects a large amount of energy, can rapidly transform the heavy Fermi liquid into a local moment state. Upon cooling, the heavy Fermi liquid reappears in a two-stage relaxation, where the first step opens the Kondo gap and the second step corresponds to a slow approach of the equilibrium state via a nonthermal pathway.

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Philipp Werner, Martin Eckstein. 2012-04-24. Relaxation dynamics of the Kondo lattice model. https://doi.org/10.1103/physrevb.86.045119

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