TY - JOUR
T1 - Density and spin modes in imbalanced normal Fermi gases from collisionless to hydrodynamic regime
AU - Narushima, Masato
AU - Watabe, Shohei
AU - Nikuni, Tetsuro
N1 - Funding Information:
SW was supported by JSPS KAKENHI Grant No. JP16K17774. TN was supported by JSPS KAKENHI Grant No. JP16K05504.
Publisher Copyright:
© 2018 IOP Publishing Ltd.
PY - 2018/1/29
Y1 - 2018/1/29
N2 - We study the mass-and population-imbalance effect on density (in-phase) and spin (out-of-phase) collective modes in a two-component normal Fermi gas. By calculating the eigenmodes of the linearized Boltzmann equation as well as the density/spin dynamic structure factor, we show that mass-and population-imbalance effects offer a variety of collective mode crossover behaviors from collisionless to hydrodynamic regimes. The mass-imbalance effect shifts the crossover regime to the higher-temperature, and a significant peak of the spin dynamic structure factor emerges only in the collisionless regime. This is in contrast to the case of mass-and population-balanced normal Fermi gases, where the spin dynamic response is always absent. Although the population-imbalance effect does not shift the crossover regime, the spin dynamic structure factor survives both in the collisionless and hydrodynamic regimes.
AB - We study the mass-and population-imbalance effect on density (in-phase) and spin (out-of-phase) collective modes in a two-component normal Fermi gas. By calculating the eigenmodes of the linearized Boltzmann equation as well as the density/spin dynamic structure factor, we show that mass-and population-imbalance effects offer a variety of collective mode crossover behaviors from collisionless to hydrodynamic regimes. The mass-imbalance effect shifts the crossover regime to the higher-temperature, and a significant peak of the spin dynamic structure factor emerges only in the collisionless regime. This is in contrast to the case of mass-and population-balanced normal Fermi gases, where the spin dynamic response is always absent. Although the population-imbalance effect does not shift the crossover regime, the spin dynamic structure factor survives both in the collisionless and hydrodynamic regimes.
KW - Boltzmann equation
KW - collisionless zero sound
KW - density (in-phase) mode
KW - hydrodynamic first sound
KW - mass-and population-imbalance effect
KW - spin (out-of-phase) mode
KW - two-component normal Fermi gas
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U2 - 10.1088/1361-6455/aaa594
DO - 10.1088/1361-6455/aaa594
M3 - Article
AN - SCOPUS:85045648630
VL - 51
JO - Journal of Physics B: Atomic, Molecular and Optical Physics
JF - Journal of Physics B: Atomic, Molecular and Optical Physics
SN - 0953-4075
IS - 5
M1 - 055202
ER -