1.Indian Institute of Science Education and Research-Kolkata,Nadia,India;2.Visva-Bharati,Santiniketan,India
Abstract:
We consider a prototypical system of an infinite range transverse field Ising model coupled to a bosonic bath. By integrating out the bosonic degrees, an effective anisotropic Heisenberg model is obtained for the spin system. The phase diagram of the latter is calculated as a function of coupling to the heat bath and the transverse magnetic field. Collective excitations at low temperatures are assessed within a spin-wave like analysis that exhibits a vanishing energy gap at the quantum critical point. We also discuss the possible realization and application of the model in different physical systems.