Bichromatic fluctuations in symmetric double well potentials: Localization and control of tunneling

Abstract

We have studied the effects of spatial symmetry-preserving bichromatic fluctuations in symmetric double well systems. The rate of tunneling is enhanced or suppressed depending on the temporal nature of fluctuations, number of fluctuation frequencies, the commensurability of the frequencies or the lack of it, fluctuation intensities, etc. Localization with complete quenching of tunneling, however occurs only when a symmetry-breaking perturbation is applied. The tunneling dynamics of the system is studied using the time-dependent Fourier grid Hamiltonian method and the analysis is done using the Floquet technique and the time-dependent Hellmann–Feynman theorem. We predict that by controlling the frequency and intensity ratios and the spatio-temporal nature of the fluctuating fields, a wide variety of situations can be created for effective control of tunneling.