Dynamic density structure factor of a unitary Fermi gas at finite temperature
نویسندگان
چکیده
Wepresent a theoretical investigation of the dynamic density structure factor of a strongly interacting Fermi gas near the Feshbach resonance atfinite temperature, which can be exploited in two photon Bragg scattering experiments. This study is based on a fully gauge invariant linear response theory, which is consistent with a diagrammatic approach for the equilibrium state taking into account the pairfluctuation effects and respects important restrictions like the f-sum rule. At small incoming momentum, the dynamic density structure factor exhibits various features including theNambuGoldstone-mode peak and the quasiparticle-scattering, pairing-breaking continua. At large incoming momentum and at half recoil frequency, the structure factor has a qualitatively similar behavior as the order parameter, which can signify the appearance of the condensate. These results qualitatively agree with the recent Bragg spectroscopy experiments.
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تاریخ انتشار 2018