论文标题
中子物质中的BCS-BEC交叉效应和伪合成
BCS-BEC Crossover Effects and Pseudogap in Neutron Matter
论文作者
论文摘要
由于较大的中子 - 中子散射长度，稀释中子物质类似于单一的费米气体，该气体位于从弱耦合的库珀对的BCS阶段到二聚体的Bose-Einstein凝结物的交叉中的一半。我们以类比与超低原子物理学中使用的T矩阵理论进行了类比讨论，我们将其推广到不可分离的有限范围相互作用的情况下。标准Nozieres-Schmitt-Rink方法的问题以及解决该方法的不同方法。结果表明，在强耦合方面，光谱函数在临界温度T_C的温度下表现出伪空隙。相关密度对T_C密度依赖性的影响很弱，但是由于降低的准粒子重量而引起的可能重要的效果。
Due to the large neutron-neutron scattering length, dilute neutron matter resembles the unitary Fermi gas, which lies half-way in the crossover from the BCS phase of weakly coupled Cooper pairs to the Bose-Einstein condensate of dimers. We discuss crossover effects in analogy with the T-matrix theory used in the physics of ultracold atoms, which we generalize to the case of a non-separable finite-range interaction. A problem of the standard Nozieres-Schmitt-Rink approach and different ways to solve it are discussed. It is shown that in the strong-coupling regime, the spectral function exhibits a pseudo-gap at temperatures above the critical temperature T_c. The effect of the correlated density on the density dependence of T_c is found to be rather weak, but a possibly important effect due to the reduced quasiparticle weight is identified.
