We study the dispersion relation of the excitation mode in a spin-polarized Fermi gas. In the frame of the imaginary-time finite temperature field theory, the polarization tensor is calculated by taking the random phase approximation. The population imbalance effects on the dispersion relation of the excitation mode and the spin-spin correlation susceptibility are investigated. The numerical results in terms of the imbalance ratio indicate the polarization effects on the dispersion relation and susceptibility χ.We study the dispersion relation of the excitation mode in a spin-polarized Fermi gas. In the frame of the imaginary-time finite temperature field theory, the polarization tensor is calculated by taking the random phase approximation. The population imbalance effects on the dispersion relation of the excitation mode and the spin-spin correlation susceptibility are investigated. The numerical results in terms of the imbalance ratio indicate the polarization effects on the dispersion relation and susceptibility χ.

Chinese Physics BMar 1, 20120 citations

Spin dynamics in spin polarized Fermi gases

A. E. Meyerovich, S. Stepaniants, Franck Laloë

Jan 1, 19950 citations

Zeroth Sound Modes of Dilute Fermi Gas with Arbitrary Spin

Sungkit Yip, Tin-Lun, Ho

Motivated by the recent success of optical trapping of alkali bosons, we have studied the zeroth sound modes of dilute Fermi gases with arbitrary spin-f, which are spin-S excitations ( $0\leq S\leq 2f$ ). The dispersion of the mode (S) depends on a single Landau parameter $F^{(S)}$ , which is related to the scattering lengths of the system through a simple formula. Measurement of (even a subset of) these modes in finite magnetic fields will enable one to determine all the interaction parameters of the system.Motivated by the recent success of optical trapping of alkali bosons, we have studied the zeroth sound modes of dilute Fermi gases with arbitrary spin-f, which are spin-S excitations ($0\leq S\leq 2f$). The dispersion of the mode (S) depends on a single Landau parameter $F^{(S)}$, which is related to the scattering lengths of the system through a simple formula. Measurement of (even a subset of) these modes in finite magnetic fields will enable one to determine all the interaction parameters of the system.

arXiv:cond-mat/9810064Oct 6, 19980 citations

Degeneracy effects in the spin dynamics of spin-polarized Fermi gases

A. E. Meyerovich

Physics Letters AJan 1, 198563 citations

Fermi liquid effects in spin polarized gases

A. E. Meyerovich, Sergey B. Stepaniants, Franck Laloë

Jan 1, 19950 citations

Excitation spectra of one-dimensional spin-1/2 Fermi gas with an attraction

Jia-Feng Pan, Jiajia Luo, Xi‐Wen Guan

Abstract Using an exact Bethe ansatz solution, we rigorously study excitation spectra of the spin-1/2 Fermi gas (called Yang–Gaudin model) with an attractive interaction. Elementary excitations of this model involve particle-hole excitation, hole excitation and adding particles in the Fermi seas of pairs and unpaired fermions. The gapped magnon excitations in the spin sector show a ferromagnetic coupling to the Fermi sea of the single fermions. By numerically and analytically solving the Bethe ansatz equations and the thermodynamic Bethe ansatz equations of this model, we obtain excitation energies for various polarizations in the phase of the Fulde–Ferrell–Larkin–Ovchinnikov-like state. For a small momentum (long-wavelength limit) and in the strong interaction regime, we analytically obtained their linear dispersions with curvature corrections, effective masses as well as velocities in particle-hole excitations of pairs and unpaired fermions. Such a type of particle-hole excitations display a novel separation of collective motions of bosonic modes within paired and unpaired fermions. Finally, we also discuss magnon excitations in the spin sector and the application of Bragg spectroscopy for testing such separated charge excitation modes of pairs and single fermions.Abstract Using an exact Bethe ansatz solution, we rigorously study excitation spectra of the spin-1/2 Fermi gas (called Yang–Gaudin model) with an attractive interaction. Elementary excitations of this model involve particle-hole excitation, hole excitation and adding particles in the Fermi seas of pairs and unpaired fermions. The gapped magnon excitations in the spin sector show a ferromagnetic coupling to the Fermi sea of the single fermions. By numerically and analytically solving the Bethe ansatz equations and the thermodynamic Bethe ansatz equations of this model, we obtain excitation energies for various polarizations in the phase of the Fulde–Ferrell–Larkin–Ovchinnikov-like state. For a small momentum (long-wavelength limit) and in the strong interaction regime, we analytically obtained their linear dispersions with curvature corrections, effective masses as well as velocities in particle-hole excitations of pairs and unpaired fermions. Such a type of particle-hole excitations display a novel separation of collective motions of bosonic modes within paired and unpaired fermions. Finally, we also discuss magnon excitations in the spin sector and the application of Bragg spectroscopy for testing such separated charge excitation modes of pairs and single fermions.

arXiv:2208.00212Communications in Theoretical PhysicsSep 15, 20224 citations

Motivated by the recent success of optical trapping of alkali bosons, we have studied the zeroth sound modes of dilute Fermi gases with arbitrary spin-f, which are spin-S excitations (

0\leq S\leq 2f

). The dispersion of the mode (S) depends on a single Landau parameter

F^{(S)}

, which is related to the scattering lengths of the system through a simple formula. Measurement of (even a subset of) these modes in finite magnetic fields will enable one to determine all the interaction parameters of the system.