6533b883fe1ef96bd12ddf84

RESEARCH PRODUCT

Dynamics of a Driven Dissipative Quantum System

Luca Magazzu'

subject

Quantum systems with finite Hilbert spaceFluctuation phenomena random processes noise and Brownian motionquantum statistical methodDecoherenceopen systemSettore FIS/03 - Fisica Della Materia

description

We investigate the dynamics of a driven multilevel system, consisting of a particle in an asymmetric bistable potential, strongly interacting with a thermal bath according to the Caldeira-Leggett model. The populations in the discrete (position) variable representation (DVR), are obtained as solution of a Markovian approximated master equation, which is derived from a discretized path integral approach based on the Feynman-Vernon influence functional. By varying the environmental parameters (temperature and coupling strength) as well as the driving frequency and amplitude, we study the transient dynamics and stationary configuration of the system. In particular, we analyze the population of the metastable well. The asymptotic population of the metastable well displays a strong non-monotonicity, characterized by a maximum, as a function of the driving frequency. We find also that an increase of the coupling strength inhibits this effect of induced stability and slows down the dynamics, forcing the system towards the relaxation.

http://hdl.handle.net/10447/83747