论文标题
在立方晶格上扩展有吸引力的哈伯德模型的电荷不稳定性
Charge instabilities of the extended attractive Hubbard Model on the cubic lattice
论文作者
论文摘要
在零温度下，在自旋旋转不变的kotliar-ruckenstein从奴隶玻色子表示中研究了立方晶格上扩展有吸引力的哈伯德模型的顺磁相。可以获得Fermi液相的准粒子残留物在所有密度的相互作用强度下消失，略小于$ u_c $，该$ u_c $信号为Brinkman-rice Transition，并且弱取决于密度。对于消失的非本地交互参数，在一个相当狭窄的窗口中发现了均匀的静态电荷不稳定性，该窗口左右左右填充和$ u \ simeq 0.8 \ u_c $，将它们增加到$ v = -0.2 \ u $结果，结果陷入了严重的窗口。相反，当所有交互参数都吸引人时，例如，对于$ v = 0.2 \ u $，找到均匀的静态电荷不稳定性的大参数范围。然而，这种系统地发生在费米液相内。
The paramagnetic phase of the extended attractive Hubbard model on the cubic lattice is studied within the spin rotation invariant Kotliar-Ruckenstein slave-boson representation at zero temperature. It is obtained that the quasiparticle residue of the Fermi liquid phase vanishes for all densities at an interaction strength slightly smaller than $U_c$ that signals the Brinkman-Rice transition, and that it weakly depends on density. While for vanishing non-local interaction parameters homogeneous static charge instabilities are found in a rather narrow window centered around quarter filling and $U \simeq 0.8\ U_c$, increasing them to $V = -0.2\ U$ results into a severe narrowing of this window. On the contrary, when all interaction parameters are attractive, for example for $V = 0.2\ U$, a large parameter range in which homogeneous static charge instabilities is found. Yet, this systematically happens inside the Fermi liquid phase.
