The Bose-Fermi Kondo model with a singular dissipative spectrum: Exact solutions and their implications

Dai, Jianhui; Si, Qimiao; Bolech, C. J.

The Bose-Fermi Kondo model with a singular dissipative spectrum: Exact solutions and their implications

Authors

Dai, Jianhui

Si, Qimiao

Bolech, C. J.

Description

Quantum dissipation induces a critical destruction of a Kondo screened state, which is of interest in the contexts of quantum critical heavy fermion metals and magnetic nanostructures. The sub-ohmic Bose-Fermi Kondo model provides a setting to study this effect. We find that this many-body problem is exactly solvable when the spectrum of the dissipative bosonic bath, J(ω), is singular, corresponding to J(τ)=const.. We determine the local spin correlation functions, showing that the singular LONGITUDINAL fluctuations of the bosonic bath dominate over the transverse ones. Our results provide evidence that the local quantum critical solution, derived within the extended dynamical mean field approach to the Kondo lattice model, has a zero residual entropy.
(v2) shortened and typos corrected; (v1) 5 pages, 2 figures