PATH-INTEGRAL MONTE-CARLO APPROACH TO THE QUANTUM DECAY-RATE OF A METASTABLE STATE WITH COORDINATE-DEPENDENT INERTIA AND FRICTION

We develop a path-integral Monte Carlo method to calculate the stationary quantum decay rate of a metastable system with coordinate-dependent inertia and friction at finite temperature. The mass and the coupling form factor between the collective coordinate and the heat-bath environmental oscillators are assumed to be functions of the coordinate, respectively. Applying the results to a spectrum of heat-bath oscillators, large influences of the coordinate-dependent mass on the decay rate are found at high temperatures, while large nonlinear effects of dissipation are found at low temperatures.