Ultracold Bosons in a Tilted Multilevel Double-Well Potential

D. R. Dounas-Frazer, A. M. Hermundstad, L. D. Carr
2007 Physical Review Letters  
The N -body problem in a double well requires new features for quantum information processing, macroscopic quantum superposition, and other fundamental studies of quantum many body physics in ultracold atoms. One needs (a) tilt, and (b) to go beyond the single-particle ground state in each well, i.e., to two or more energy levels. For (a), we show that a small potential difference between the wells, or tilt, causes the decoherence of Schrodinger cat states. However, these states reappear when
more » ... e tilt can be compensated by atom-atom interactions; these tilted cat states constitute partial cats that are protected from decoherence by the many body wavefunction. For (b), we provide explicit criteria for when two energy levels are needed to describe the state space. For typical experimental parameters, two levels are indeed required for creation of cat states.
doi:10.1103/physrevlett.99.200402 pmid:18233123 fatcat:yldhz3u4bvhhhalhtwjxjas3ca