Issue |
EPL
Volume 79, Number 5, September 2007
|
|
---|---|---|
Article Number | 50003 | |
Number of page(s) | 6 | |
Section | General | |
DOI | https://doi.org/10.1209/0295-5075/79/50003 | |
Published online | 08 August 2007 |
Tightly bound gap solitons in a Fermi gas
1
Instituto de Física Teórica, UNESP – São Paulo State University - 01.405-900 São Paulo, São Paulo, Brazil
2
Department of Physical Electronics, School of Electrical Engineering, Faculty of Engineering, Tel Aviv University - Tel Aviv 69978, Israel
Received:
12
February
2007
Accepted:
18
July
2007
Within the framework of the mean-field hydrodynamic model of a degenerate Fermi gas (DFG), we study, by means of
numerical methods and variational approximation (VA), the formation of fundamental gap solitons (FGSs) in a DFG (or in a BCS
superfluid generated by weak interaction between spin-up and spin-down fermions), which is trapped in a periodic
optical-lattice (OL) potential. An effectively one-dimensional (1D) configuration is considered, assuming strong transverse
confinement; in parallel, a proper 1D model of the DFG (which amounts to the known quintic equation for the Tonks-Girardeau gas
in the OL) is considered too. The FGSs found in the first two bandgaps of the OL-induced spectrum (unless they are
very close to edges of the gaps) feature a (tightly bound)
shape, being essentially confined to a single cell of the OL. In the second bandgap, we also find antisymmetric tightly bound subfundamental solitons (SFSs), with zero at the midpoint. The
SFSs are also confined to a single cell of the OL, but, unlike the FGSs, they are unstable. The predicted solitons, consisting of
atoms, can be created by available experimental
techniques in the DFG of 6Li atoms.
PACS: 03.75.Ss – Degenerate Fermi gases / 03.75.Lm – Tunneling, Josephson effect, Bose-Einstein condensates in periodic potentials, solitons, vortices, and topological excitations / 05.45.Yv – Solitons
© Europhysics Letters Association, 2007
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.