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 station ary quantum decay rate of a metastable system with coordinate-dependen t inertia and friction at finite temperature. The mass and the couplin g form factor between the collective coordinate and the heat-bath envi ronmental oscillators are assumed to be functions of the coordinate, r espectively. Applying the results to a spectrum of heat-bath oscillato rs, large influences of the coordinate-dependent mass on the decay rat e are found at high temperatures, while large nonlinear effects of dis sipation are found at low temperatures.