arXiv:1102.5326 · Physical Review Letters
Laser Controlled Tunneling in a Vertical Optical Lattice
Quentin Beaufils, Gunnar Tackmann, X. Wang, Bruno Pelle, Sophie Pelisson, Peter Wolf, Franck Pereira dos Santos
Abstract
Raman laser pulses are used to induce coherent tunneling between neighboring sites of a vertical 1D optical lattice. Such tunneling occurs when the detuning of a probe laser from the atomic transition frequency matches multiples of the Bloch frequency, allowing for a spectroscopic control of the coupling between Wannier-Stark (WS) states. In particular, we prepare coherent superpositions of WS states of adjacent sites, and investigate the coherence time of these superpositions by realizing a spatial interferometer. This scheme provides a powerful tool for coherent manipulation of external degrees of freedom of cold atoms, which is a key issue for quantum information processing.