The Bose–Fermi Kondo model in an exactly solvable limit

Abstract

The Bose–Fermi Kondo model (BFKM) has a rich phase diagram which is sensitive to χ 0 - 1 ( ω ) ∝ | ω | 1 - ε , the spectral density of the dissipative bosonic bath. Here, we show that the SU ( 2 ) BFKM is exactly solvable by the Bethe Ansatz method if the dissipative bosonic bath has a singular spectrum, corresponding to ε = 2 , or χ 0 - 1 ( τ ) = const . The exact solution explicitly demonstrates a destruction of Kondo screening by the coupling to the dissipative bosonic bath.