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Local phonon mode in a fermionic bath, and its relation to Kondo effect

Balázs Dóra
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Abstract

We have studied the interplay of a local phonon mode embedded in a metallic host (Holstein impurity model) using Abelian bosonization. The phonon frequency softens, which takes place in two steps: first, their frequency starts softening, and acquires finite lifetime. Then oscillations disappear from the response, and two distinct, finite dampings characterize them. Similar behaviour shows up in the spin-boson model. Due to phonons, the electrons experience an attractive, dynamic interaction. As a result, the electronic charge response enhances similarly to the spin response in the Kondo model. The local electronic density of states develops a dip around zero frequency. Thus the chance of charge-Kondo effect emerges.

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Balázs Dóra. 2007-06-06. Local phonon mode in a fermionic bath, and its relation to Kondo effect. https://doi.org/10.1103/physrevb.75.245113

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