Tunneling through a fluctuating barrier: Two-level model

We investigate the problem of tunneling across a randomly fluctuating barri er in the presence of dissipation in the two-level approximation. The barri er fluctuations are induced by a random telegraph noise whose switching rat e v is taken as a control parameter. For infinitely fast fluctuations the d ynamics of the system is similar to the static case, while, for very small v, the barrier evolution is a superposition of static solutions for both co nfigurations. This leads to a resonant beating or long-time periodic locali zation. For an intermediate value of v we have found a resonancelike suppre ssion of coherent tunneling. When the system levels are detuned, a resonant enhancement of decay in the incoherent regime also occurs.