Collective Excitations of an Imbalanced Fermion Gas in a 1D Optical Lattice

2013/07/10 by Rafael Mendoza, R. Mendoza, M. Fortes +2
Chemistry · Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Fermion #Hamiltonian (control theory) #Helmholtz free energy #Hubbard model #Lattice (music) #Optical lattice #Phase (matter) #Phase diagram #Physics #Quantum mechanics #Quantum optics and atomic interactions #Quasiparticle #Random phase approximation #Spectroscopy and Laser Applications #Superconductivity #Superfluidity #cond-mat.quant-gas

paper · pdf · doi:10.1007/s10909-013-0926-2

Six pages and 3 figures

arxiv created 2013/07/10 · openalex publication_date 2013/09/30 · arxiv updated 2015/06/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

The collective excitations that minimize the Helmholtz free energy of a population-imbalanced mixture of a ⁶Li gas loaded in a quasi one-dimensional optical lattice are obtained. These excitations reveal a rotonic branch after solving the Bethe-Salpeter equation under a generalized random phase approximation based on a single-band Hubbard Hamiltonian. The phase diagram describing stability regions of Fulde-Farrell-Larkin-Ovchinnikov and Sarma phases is also analyzed.

Citations

• Noise correlations of the ultracold Fermi gas in an optical lattice
• Fulde-Ferrell-Larkin-Ovchinnikov pairing in one-dimensional optical lattices
• Finite-Temperature Phase Diagram of a Polarized Fermi Gas in an Optical Lattice
• Quantum phase diagram of fermion mixtures with population imbalance in one-dimensional optical lattices
• Collective modes and the speed of sound in the Fulde-Ferrell-Larkin-Ovchinnikov state
• Imbalanced Feshbach-resonant Fermi gases
• The Fulde–Ferrell–Larkin–Ovchinnikov phase in the presence of pair hopping interaction
• Fermi surfaces and Luttinger’s theorem in paired fermion systems
• Oscillatory pairing amplitude and magnetic compressible-incompressible transitions in imbalanced fermionic superfluids in optical lattices of elongated tubes
• Finite-temperature phase diagram of a spin-polarized ultracold Fermi gas in a highly elongated harmonic trap
• Fermion pairing with spin-density imbalance in an optical lattice