Nonlinear effects in periodic potentials: asymmetric Landau-Zener tunnelling of a Bose-Einstein condensate
✍ Scribed by M. Jona-Lasinio; O. Morsch; M. Cristiani; N. Malossi; J. H. Müller; E. Courtade; M. Anderlini; E. Arimondo
- Publisher
- John Wiley and Sons
- Year
- 2004
- Tongue
- English
- Weight
- 394 KB
- Volume
- 1
- Category
- Article
- ISSN
- 1612-2011
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✦ Synopsis
From a two-level model for nonlinear Landau-Zener
tunnelling between two energy bands of a Bose-Einstein condensate
in a periodic potential we obtain unequal tunnelling rates for the
two directions of tunnelling. With increasing nonlinearity,
tunnelling from the ground state to the excited state is enhanced,
whereas in the opposite direction it is suppressed. These findings
are confirmed by numerical simulations of the condensate dynamics.
Measuring the tunnelling rates for a condensate of rubidium atoms
in an optical lattice, we have found experimental evidence for
this asymmetry. We discuss the limitations of our approach and
possible future experiments.