Diffusion in the time-dependent double-well potential

We investigate the one-dimensional diffusion of a particle in a piecewise linear W-shaped potential, on which a harmonically modulated discontinuity situated at the central tip is superimposed. The simplified description of the external driving enables an exact analysis of the emerging non-linear dynamics. The response is represented by the occupation difference between the regions of attraction of the right and the left minima of the potential profile. We discuss the time-asymptotic and time-averaged occupational differences as a function of the temperature, the amplitude and the frequency of the driving. We compare the analysis with the corresponding results based on the popular two-state description of the underlying resonance effects. The comparison reveals the fundamental role of the intra-well dynamics within the space-continuous formulation.