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arXiv · 1307.5488

Spatiotemporal buildup of the Kondo screening cloud

M. Medvedyeva·A. Hoffmann·S. Kehrein
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Abstract

We investigate how the Kondo screening cloud builds up as a function of space and time. Starting from an impurity spin decoupled from the conduction band, the Kondo coupling is switched on at time t=0. We work at the Toulouse point where one can obtain exact analytical results for the ensuing spin dynamics at both zero and nonzero temperature T. For t>0 the Kondo screening cloud starts building up in the wake of the impurity spin being transported to infinity. In this buildup process the impurity spin--conduction band spin susceptibility shows a sharp light cone due to causality, while the corresponding correlation function has a tail outside the light cone. At T=0 this tail has a power law decay as a function of distance from the impurity, which we interpret as due to initial entanglement in the Fermi sea.

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M. Medvedyeva, A. Hoffmann, S. Kehrein. 2013-07-21. Spatiotemporal buildup of the Kondo screening cloud. https://doi.org/10.1103/physrevb.88.094306

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