Publication
Title
Finite temperature effective field theory and two-band superfluidity in Fermi gases
Author
Abstract
We develop a description of fermionic superfluids in terms of an effective field theory for the pairing order parameter. Our effective field theory improves on the existing Ginzburg-Landau theory for superfluid Fermi gases in that it is not restricted to temperatures close to the critical temperature. This is achieved by taking into account long-range fluctuations to all orders. The results of the present effective field theory compare well with the results obtained in the framework of the Bogoliubov-de Gennes method. The advantage of an effective field theory over Bogoliubov-de Gennes calculations is that much less computation time is required. In the second part of the paper, we extend the effective field theory to the case of a two-band superfluid. The present theory allows us to reveal the presence of two healing lengths in the two-band superfluids, to analyze the finite-temperature vortex structure in the BEC-BCS crossover, and to obtain the ground state parameters and spectra of collective excitations. For the Leggett mode our treatment provides an interpretation of the observation of this mode in two-band superconductors.
Language
English
Source (journal)
European physical journal : B : condensed matter and complex systems. - Berlin
Publication
Berlin : 2015
ISSN
1434-6028
Volume/pages
88:5(2015), 17 p.
Article Reference
122
ISI
000354198500015
Medium
E-only publicatie
Full text (Publishers DOI)
Full text (open access)
Full text (publishers version - intranet only)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 11.06.2015
Last edited 06.03.2017
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