| Автор | Martin Holthaus |
| Дата выпуска | 2000-10-01 |
| dc.description | We study the dynamics of ultracold atoms in an optical lattice under constant bias. After recapitulating the ideas underlying Bloch oscillations and Zener's formula for interband transitions, the Bloch-Zener scenario is tested by means of accurate numerical solutions to the time-dependent Schrödinger equation. It is shown how two shortcomings of the traditional Zener formula can be removed: the common weak-binding approximation can be circumvented by combining Kohn's insight into the structure of complex energy bands with the Dykhne-Davis-Pechukas description of transitions in terms of adiabatic excursions on analytically continued eigenvalue surfaces, and a usually neglected Stokes phenomenon comes into play when accounting for the finite width of the Brillouin zone. Treating Bose-Einstein condensates in optical lattices within the standard mean-field approximation at zero temperature, the ideal Bloch-Zener scenario turns out to be remarkably stable against the condensate's nonlinear self-interaction. Yet, under appropriate conditions a Bloch-oscillating Gross-Pitaevskii wavepacket reveals characteristic signatures of that nonlinearity, such as sudden phase jumps, slight shifts of the oscillation frequency or non-classical breathing modes. It is suggested that such experimentally detectable signatures will play an important role in future high-precision experiments aiming at the exploration of many-body dynamics in periodic potentials with condensates in optical lattices. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | Bloch oscillations and Zener breakdown in an optical lattice |
| Тип | paper |
| DOI | 10.1088/1464-4266/2/5/306 |
| Electronic ISSN | 1741-3575 |
| Print ISSN | 1464-4266 |
| Журнал | Journal of Optics B: Quantum and Semiclassical Optics |
| Том | 2 |
| Первая страница | 589 |
| Последняя страница | 604 |
| Аффилиация | Martin Holthaus; Ludwig-Maximilians-Universität, Sektion Physik, Theresienstraße 37, D-80333 München, Germany |
| Выпуск | 5 |
