We study response functions of integrable quantum impurity problems with an external field at T = 0 using non perturbative techniques derived from the Bethe ansatz. We develop the first steps of the theory of excitations over the new, field dependent ground state, leading to renormalized (or “dressed”) form-factors. We obtain exactly the low frequency behaviour of the dynamical susceptibility χ ′ ′ (ω) in the double well problem of dissipative quantum mechanics (or equivalently the anisotropic Kondo problem), and the low frequency behaviour of the AC noise St(ω) for tunneling between edges in fractional quantum Hall devices. We also obtain exactly the structure of singularities in χ ′ ′ (ω) and St(ω). Our results differ significantly from previous perturbative approaches. 10/96 1. Introduction. One dimensional quantum impurity problems, which are of considerable physical importance, have recently been the subject of significant theoretical progresses based on their integrability. In particular, in a recent paper , we have shown how correlation functions at T = 0 and without an applied field could be obtained 1 using massless form-factor
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.