Collective Modes of an Ultracold 6Li-40K Mixture in an Optical Lattice
Author
Source
Advances in Condensed Matter Physics
Issue
Vol. 2015, Issue 2015 (31 Dec. 2015), pp.1-12, 12 p.
Publisher
Hindawi Publishing Corporation
Publication Date
2015-11-08
Country of Publication
Egypt
No. of Pages
12
Main Subjects
Abstract EN
A low-energy theory of the Nambu-Goldstone excitation spectrum and the corresponding speed of sound of an interacting Fermi mixture of Lithium-6 andPotassium-40 atoms in a two-dimensional optical lattice at finitetemperatures with the Fulde-Ferrell order parameter has been formulated.
It is assumed that the two-species interacting Fermi gas is described by the one-band Hubbard Hamiltonian with an attractive on-site interaction.
The discussion is restricted to the BCS side of the Feshbach resonance where the Fermi atoms exhibit superfluidity.
The quartic on-site interaction is decoupled via a Hubbard-Stratonovich transformation by introducing a four-component boson field which mediates the Hubbard interaction.
A functional integral technique and a Legendre transform are used to give a systematic derivation of the Schwinger-Dyson equations for the generalized single-particle Green’s function and the Bethe-Salpeter equation for the two-particle Green’s function and the associated collective modes.
The numerical solution of the Bethe-Salpeter equation in the generalized random phase approximation shows that there exist two distinct soundvelocities in the long-wavelength limit.
In addition to low-energy(Goldstone) mode, the two-species Fermi gas has a superfluid phase revealed by two roton-like minima in the asymmetric collective-mode energy.
American Psychological Association (APA)
Koinov, Z. G.. 2015. Collective Modes of an Ultracold 6Li-40K Mixture in an Optical Lattice. Advances in Condensed Matter Physics،Vol. 2015, no. 2015, pp.1-12.
https://search.emarefa.net/detail/BIM-1052332
Modern Language Association (MLA)
Koinov, Z. G.. Collective Modes of an Ultracold 6Li-40K Mixture in an Optical Lattice. Advances in Condensed Matter Physics No. 2015 (2015), pp.1-12.
https://search.emarefa.net/detail/BIM-1052332
American Medical Association (AMA)
Koinov, Z. G.. Collective Modes of an Ultracold 6Li-40K Mixture in an Optical Lattice. Advances in Condensed Matter Physics. 2015. Vol. 2015, no. 2015, pp.1-12.
https://search.emarefa.net/detail/BIM-1052332
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references
Record ID
BIM-1052332