scholarly journals Speed of the Goldstone Sound Mode of an Atomic Fermi Gas Loaded on a Square Optical Lattice with a Non-Abelian Gauge Field in the Presence of a Zeeman Field

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Zlatko Koinov ◽  
Israel Chávez Villalpando
Keyword(s):  
Gauge Field ◽  
Optical Lattice ◽  
Gaussian Approximation ◽  
Fermi Gas ◽  
Sharp Change ◽  
Goldstone Mode ◽  
Abelian Gauge ◽  
Zeeman Field ◽  
Sound Mode ◽  
Atomic Fermi Gas

The speed of the Goldstone sound mode of a spin-orbit-coupled atomic Fermi gas loaded in a square optical lattice with a non-Abelian gauge field in the presence of a Zeeman field is calculated within the Gaussian approximation and from the Bethe-Salpeter equation in the generalized random phase approximation. It is found that (i) there is no sharp change of the slope of the Goldstone sound mode across the topological quantum phase transition point and (ii) the Gaussian approximation significantly overestimates the speed of sound of the Goldstone mode compared to the value provided by the BS formalism.

scholarly journals Collective Modes of an Ultracold6Li-40K Mixture in an Optical Lattice

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Z. G. Koinov
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Optical Lattice ◽  
Random Phase ◽  
Fermi Gas ◽  
Functional Integral ◽  
Low Energy ◽  
Collective Modes ◽  
Legendre Transform ◽  
Goldstone Mode

A low-energy theory of the Nambu-Goldstone excitation spectrum and the corresponding speed of sound of an interacting Fermi mixture of Lithium-6 and Potassium-40 atoms in a two-dimensional optical lattice at finite temperatures 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 sound velocities 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.

scholarly journals Polarization plateau in an atomic Fermi gas loaded on a three-leg triangular optical lattice

2009 ◽  
Vol 79 (6) ◽  
Author(s):  
M. Okumura ◽  
S. Yamada ◽  
M. Machida ◽  
T. Sakai
Keyword(s):  
Optical Lattice ◽  
Fermi Gas ◽  
Atomic Fermi Gas

scholarly journals Free fermion antibunching in a degenerate atomic Fermi gas released from an optical lattice

Nature ◽  
2006 ◽  
Vol 444 (7120) ◽  
pp. 733-736 ◽  
Author(s):  
T. Rom ◽  
Th. Best ◽  
D. van Oosten ◽  
U. Schneider ◽  
S. Fölling ◽  
...  
Keyword(s):  
Optical Lattice ◽  
Fermi Gas ◽  
Free Fermion ◽  
Atomic Fermi Gas

Kohn–Sham theory of an atomic Fermi gas

2008 ◽  
Vol 372 (12) ◽  
pp. 2048-2049
Author(s):  
Guilherme S. Nunes
Keyword(s):  
Fermi Gas ◽  
Atomic Fermi Gas

Magnetic-Field Dependence of Raman Coupling Strength in Ultracold 40 K Atomic Fermi Gas

2016 ◽  
Vol 33 (3) ◽  
pp. 033401
Author(s):  
Liang-Hui Huang ◽  
Peng-Jun Wang ◽  
Zeng-Ming Meng ◽  
Peng Peng ◽  
Liang-Chao Chen ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Dependence ◽  
Coupling Strength ◽  
Magnetic Field Dependence ◽  
Fermi Gas ◽  
Atomic Fermi Gas

scholarly journals CONSTRAINED DYNAMICS OF THE COUPLED ABELIAN TWO-FORM

1993 ◽  
Vol 08 (25) ◽  
pp. 2403-2412 ◽  
Author(s):  
AMITABHA LAHIRI
Keyword(s):  
Phase Space ◽  
Gauge Field ◽  
Antisymmetric Tensor ◽  
Abelian Gauge ◽  
Constrained Dynamics ◽  
Duality Transformations ◽  
Tensor Potential

I present the reduction of phase space of the theory of an antisymmetric tensor potential coupled to an Abelian gauge field, using Dirac's procedure. Duality transformations on the reduced phase space are also discussed.

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