title: Dissipative dynamics in a quantum bistable system: crossover from weak to strong damping.
abstract: The dissipative dynamics of a quantum bistable system coupled to a Ohmic heat bath is investigated beyond the spin-boson approximation. Within the path-integral approach to quantum dissipation, we propose an approximation scheme which exploits the separation of time scales between intra- and interwell (tunneling) dynamics. The resulting generalized master equation for the populations in a space localized basis enables us to investigate a wide range of temperatures and system-environment coupling strengths. A phase diagram in the coupling-temperature space is provided to give a comprehensive account of the different dynamical regimes.
authors.affiliation: Dipartimento di Fisica e Chimica, Università di Palermo, Viale delle Scienze, Edificio 18, I-90128 Palermo, Italy.|Radiophysics Department, Lobachevsky State University of Nizhni Novgorod, Russia.
authors.forename: Luca
authors.initials: L
authors.lastname: Magazzù
authors.affiliation: Dipartimento di Fisica e Chimica, Università di Palermo, Viale delle Scienze, Edificio 18, I-90128 Palermo, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Valenti
authors.affiliation: Dipartimento di Fisica e Chimica, Università di Palermo, Viale delle Scienze, Edificio 18, I-90128 Palermo, Italy.|Radiophysics Department, Lobachevsky State University of Nizhni Novgorod, Russia.|Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Italy.
authors.forename: Bernardo
authors.initials: B
authors.lastname: Spagnolo
authors.affiliation: Theoretische Physik, Universität Regensburg, 93040 Regensburg, Germany.
authors.forename: Milena
authors.initials: M
authors.lastname: Grifoni