Variational theory of two-fluid hydrodynamic modes at unitarity

@article{citeulike:2506649, abstract = {We present the results of a variational calculation of the frequencies of the low-lying Landau two-fluid hydrodynamic modes in a trapped Fermi superfluid gas at unitarity. Landau's two-fluid hydrodynamics is expected to be the correct theory of Fermi superfluids at finite temperatures close to unitarity, where strong interactions give rise to collisional hydrodynamics. Two-fluid hydrodynamics predicts the existence of in-phase modes in which the superfluid and normal fluid components oscillate together, as well as out-of-phase modes where the two components move against each other. We prove that, at unitarity, the dipole and breathing in-phase modes are locally isentropic. Their frequencies are independent of temperature and are the same above and below the superfluid transition, a feature due as much to the harmonic trapping potential as to the thermodynamic properties at unitarity. The out-of-phase modes, in contrast, are strongly dependent on temperature and hence can be used to test the thermodynamic properties and superfluid density of a Fermi gas at unitarity. We give numerical results for the frequencies of these modes as function of temperature in an isotropic trap at unitarity.}, author = {Taylor, E. and Hu, H. and Liu, X. J. and Griffin, A. }, citeulike-article-id = {2506649}, doi = {10.1103/PhysRevA.77.033608}, journal = {Physical Review A (Atomic, Molecular, and Optical Physics)}, keywords = {bec-bcs, fermion, hydrodynamics, unitarity}, number = {3}, posted-at = {2008-03-11 09:57:04}, priority = {2}, publisher = {APS}, title = {Variational theory of two-fluid hydrodynamic modes at unitarity}, url = {http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal\&id=PLRAAN000077000003033608000001\&idtype=cvips\&gifs=yes}, volume = {77}, year = {2008} }

TY - JOUR ID - citeulike:2506649 L3 - citeulike-article-id:2506649 TI - Variational theory of two-fluid hydrodynamic modes at unitarity JF - Physical Review A (Atomic, Molecular, and Optical Physics) VL - 77 IS - 3 PB - APS N2 - We present the results of a variational calculation of the frequencies of the low-lying Landau two-fluid hydrodynamic modes in a trapped Fermi superfluid gas at unitarity. Landau's two-fluid hydrodynamics is expected to be the correct theory of Fermi superfluids at finite temperatures close to unitarity, where strong interactions give rise to collisional hydrodynamics. Two-fluid hydrodynamics predicts the existence of in-phase modes in which the superfluid and normal fluid components oscillate together, as well as out-of-phase modes where the two components move against each other. We prove that, at unitarity, the dipole and breathing in-phase modes are locally isentropic. Their frequencies are independent of temperature and are the same above and below the superfluid transition, a feature due as much to the harmonic trapping potential as to the thermodynamic properties at unitarity. The out-of-phase modes, in contrast, are strongly dependent on temperature and hence can be used to test the thermodynamic properties and superfluid density of a Fermi gas at unitarity. We give numerical results for the frequencies of these modes as function of temperature in an isotropic trap at unitarity. KW - bec-bcs KW - fermion KW - hydrodynamics KW - unitarity AU - Taylor, E AU - Hu, H AU - Liu, XJ AU - Griffin, A PY - 2008/// UR - http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PLRAAN000077000003033608000001&idtype=cvips&gifs=yes ER -