Spin Susceptibility and Strong Coupling Effects in an Ultracold Fermi Gas
arXiv:1307.1301 · doi:10.1007/s10909-013-0928-0
Abstract
We investigate magnetic properties and strong coupling corrections in the BCS (Bardeen-Cooper-Schrieffer)-BEC (Bose-Einstein condensation) crossover regime of an ultracold Fermi gas. Within the framework of an extended -matrix theory, we calculate the spin susceptibility above the superfluid phase transition temperature . In the crossover region, the formation of preformed Cooper pairs is shown to cause a non-monotonic temperature dependence of , which is similar to the so-called spin-gap phenomenon observed in the under-doped regime of high- cuprates. From this behavior of , we determine the spin-gap temperature as the temperature at which takes a maximum value, in the BCS-BEC crossover region. Since the spin susceptibility is sensitive to the formation of singlet Cooper pairs, our results would be useful in considering the temperature region where pairing fluctuations are important in the BCS-BEC crossover regime of an ultracold Fermi gas.
7 pages, 3 figures, proceedings of QFS-2013
References in corpus (12)
- Many-Body Physics with Ultracold Gases
- Theory of ultracold Fermi gases
- Using photoemission spectroscopy to probe a strongly interacting Fermi gas
- Observation of pseudogap behavior in a strongly interacting Fermi gas
- Evolution of the Normal State of a Strongly Interacting Fermi Gas from a Pseudogap Phase to a Molecular Bose Gas
- Speckle Imaging of Spin Fluctuations in a Strongly Interacting Fermi Gas
- Pseudo-gap pairing in ultracold Fermi atoms
- Quantum mechanical limitations to spin diffusion in the unitary Fermi gas
- BCS-BEC crossover in an asymmetric two-component Fermi gas
- Cooper pairing above the critical temperature in a unitary Fermi gas
- Spin susceptibility and fluctuation corrections in the BCS-BEC crossover regime of an ultracold Fermi gas
- Coexistence of superfluid gap and pseudogap in the BCS-BEC crossover regime of a trapped Fermi gas below