Self-consistent T-matrix approximation to the negative-U Hubbard model: numerical results
Self-consistent T-matrix approximation to the negative-U Hubbard model: numerical results
复制标题
负 U 哈伯德模型的自洽 T 矩阵近似：数值结果
DOI：
10.1088/0953-8984/4/44/017
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
P. Wölfle
中科院分区：
文献类型：
--
作者：
R. Frésard;B. Glaser;P. Wölfle
本文在自洽T矩阵近似下研究了正方形格点上的负U Hubbard模型。他们调查的费米海的束缚态，总是发生在两个空间维度的存在下，一个吸引力的相互作用的影响。只要结合能小于费米能，这些束缚态被发现被充分加宽，费米液体的行为被恢复。只有在大结合能的极限下，人们才能期望稳定的玻色对和解离的费米子共存，从而导致费米液体理论的崩溃。
The authors consider the negative-U Hubbard model on a square lattice in the self-consistent T-matrix approximation. They investigate the influence of the Fermi sea on the bound states which always occur in two spatial dimensions in the presence of an attractive interaction. As long as the binding energy is smaller than the Fermi energy, these bound states are found to be broadened sufficiently that Fermi liquid behaviour is restored. Only in the limit of large binding energy does one expect coexisting stable Bose pairs and dissociated fermions leading to a breakdown of Fermi liquid theory.