Low-energy excitations of the one-dimensional half-filled SU(4) Hubbard model with an attractive on-site interaction: Density-matrix renormalization-group calculations and perturbation theory
Low-energy excitations of the one-dimensional half-filled SU(4) Hubbard model with an attractive on-site interaction: Density-matrix renormalization-group calculations and perturbation theory
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DOI：
10.1103/physrevb.74.233102
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发表时间：
2006-09
影响因子：
3.7
通讯作者：
Jize Zhao;K. Ueda;Xiaoqun Wang
中科院分区：
文献类型：
--
作者：
Jize Zhao;K. Ueda;Xiaoqun Wang
利用密度矩阵重整化群方法和微扰理论研究了具有吸引在位相互作用的一维半填充SU（4）Hubbard模型的低能激发.我们发现基态是一个具有长程有序的电荷密度波态。基态是完全不可压缩的，因为所有的激发都是有隙的。与四粒子激发能隙相同的电荷能隙是U的非单调函数，而自旋能隙等则随着U的增大而增大，并具有线性渐近行为.
We investigate low-energy excitations of the one-dimensional half-filled SU(4) Hubbard model with an attractive on-site interaction $Ul0$ using the density-matrix renormalization-group method as well as perturbation theory. We find that the ground state is a charge-density-wave state with long-range order. The ground state is completely incompressible since all the excitations are gapful. The charge gap, which is the same as the four-particle excitation gap, is a nonmonotonic function of $U$, while the spin gap and others increase with increasing $\ensuremath{\mid}U\ensuremath{\mid}$ and have linear asymptotic behaviors.