کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1820202 | 1525768 | 2008 | 6 صفحه PDF | دانلود رایگان |

We investigate the superfluid carrier density ρsρs in the BCS–BEC crossover regime of a Fermi superfluid at finite temperatures. Including pairing fluctuations within a Gaussian approximation, we calculate the superfluid order parameter, chemical potential, and ρsρs in a consistent manner in the whole BCS–BEC crossover region. In the weak-coupling BCS regime, the temperature dependence of ρsρs is dominated by single-particle excitations accompanied by thermal dissociation of Cooper pairs. In the strong-coupling BEC regime, we show that single-particle excitations become less dominant and thermal excitations of collective Bogoliubov mode become important for ρsρs. We clarify how the weak-coupling BCS result smoothly changes into the strong-coupling BEC result, as one increases the strength of a pairing interaction.
Journal: Physica C: Superconductivity and its Applications - Volume 468, Issues 7–10, 1 April 2008, Pages 599–604