Atom resonant tunnelling through a moving barrier

Abstract

We study the one-dimensional dynamical behaviour of an atomic wavepacketmoving across an opaque and spatially oscillating optical barrier. Thetunnelling probability shows a dramatic dependence on the frequencyof the barrier oscillation. Transmission of the atomic wavepacket is, infact, dominated by inelastic or elastic effects, depending on whether theoscillation period is comparable to or shorter than the atom–barrier interactiontime. In the elastic regime, in particular, we find that full transparencybecomes possible at energies where the stationary barrier would otherwise beessentially opaque. We predict that both inelastic and elastic resonanttunnelling regimes could be observed with atomic condensates impinging on aspatially oscillating optical barrier. A few applications will also be discussed.