Pseudogap phenomena of an ultracold Fermi gas with a p-wave Feshbach resonance
Pseudogap phenomena of an ultracold Fermi gas with a p-wave Feshbach resonance
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具有 p 波费什巴赫共振的超冷费米气体的赝能隙现象
DOI：
10.1088/1742-6596/400/1/012021
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Yoji Ohashi
中科院分区：
文献类型：
--
作者：
Daisuke Inotani;Ryota Watanabe;Manfred Sigrist;Yoji Ohashi
本文研究了具有可调波相互作用的单组分费米气体的单粒子性质。包括配对波动与此各向异性的相互作用在a-矩阵理论，我们计算的单粒子的态密度，以及光谱权重，超流转变温度以上。从弱耦合制度开始，我们表明，所谓的赝隙首先在这些数量的发展与增加的相互作用强度。然而，当相互作用变得强到一定程度时，赝能隙变得模糊，最终在中间耦合区消失。在强耦合机制中，与紧密结合的分子的形成相关的激发间隙再次打开。激发能隙的这种非单调相互作用依赖性与波相互作用的情况截然不同，在波相互作用的情况下，赝能隙只是随着相互作用强度的增加而发展，并不断变化为分子激发能隙。这两种情况之间的差异示出起源于波相互作用的动量依赖性，这消失在低动量限制。我们还确定了赝能隙制度的相图相对于温度和波的相互作用强度。由于赝能隙是超流相变的前兆现象，我们的结果将有助于研究波超流费米气体的实现。
We investigate single-particle properties of a one-component Fermi gas with a tunable-wave interaction. Including pairing fluctuations associated with this anisotropic interaction within a-matrix theory, we calculate the single-particle density of states, as well as the spectral weight, above the superfluid transition temperature. Starting from the weak-coupling regime, we show that the so-called pseudogap first develops in these quantities with increasing the interaction strength. However, when the interaction becomes strong to some extent, the pseudogap becomes obscure to eventually disappear in the intermediate coupling regime. In the strong-coupling regime, the excitation gap associated with the formation of tightly bound molecules again opens. This nonmonotonic interaction dependence of the excitation gap is quite different from the case of an-wave interaction, where the pseudogap simply develops with increasing the interaction strength, which continuously changes into the molecular excitation gap. The difference between the two cases is shown to originate from the momentum dependence of the-wave interaction, which vanishes in the low momentum limit. We also identify the pseudogap regime in the phase diagram with respect to the temperature and the-wave interaction strength. Since the pseudogap is a precursor phenomenon of the superfluid phase transition, our results would be useful for the research toward the realization of-wave superfluid Fermi gases.