Simulating quantum dissipation in many-body systems

An efficient Path Integral Monte Carlo procedure is proposed to simulate
the behavior of quantum many-body dissipative systems described within the
framework of the influence functional. Thermodynamic observables are
obtained by Monte Carlo sampling of the partition function after
discretization and Fourier transformation in imaginary time of the
dynamical variables. The method is tested extensively for model systems,
using realistic dissipative kernels. Results are also compared with the
predictions of a recently proposed semiclassical approximation, thus
testing the reliability of the latter approach for weak quantum coupling.
Our numerical method opens the possibility to quantitatively describe real
quantum dissipative systems as, e.g., Josephson junction arrays.