PHYSICAL QUANTITIES IN NEARLY ANTIFERROMAGNETIC AND SUPERCONDUCTING STATES OF THE 2-DIMENSIONAL HUBBARD-MODEL AND COMPARISON WITH CUPRATE SUPERCONDUCTORS
PHYSICAL QUANTITIES IN NEARLY ANTIFERROMAGNETIC AND SUPERCONDUCTING STATES OF THE 2-DIMENSIONAL HUBBARD-MODEL AND COMPARISON WITH CUPRATE SUPERCONDUCTORS
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DOI：
10.1103/physrevb.52.1297
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发表时间：
1995-07-01
影响因子：
3.7
通讯作者：
TEWORDT, L
中科院分区：
文献类型：
--
作者：
DAHM, T;TEWORDT, L
在涨落交换近似下，计算了半填充附近二维Hubbard模型的准粒子自能、差距函数和动态自旋磁化率对全动量和实频率的依赖关系.自旋密度波（SDW）不稳定性仅在无限大U或零温度的极限下渐近达到。在SDW不稳定性附近，我们发现近似边缘费米液体行为，赝能隙的状态密度，和单重d（x）2（-gamma）2配对不稳定性。低于Tc时，能隙在差距函数、准粒子散射率和态密度的频谱中迅速打开。的动态自旋磁化率的谱密度同意定性与La 2-xSrxCuO 4上的中子散射数据。准粒子散射速率和自旋-晶格弛豫速率T_（-1）在低于T_c时迅速下降。沿着带隙的波腹和波节的光电子强度与Bi 2212的角分辨光电子能谱数据吻合得很好。包括次近邻跳跃，我们得到足够大的耦合（U/t大于或类似于7）一个广泛的相称的中子散射峰，如在YBa 2Cu 3 O 6 +x中观察到的。
We have calculated within the fluctuation exchange approximation the full momentum and real-frequency dependence of the quasiparticle self-energy, the gap function, and the dynamic spin susceptibility for the two-dimensional Hubbard model near half filling. The spin-density-wave (SDW) instability is reached only asymptotically in the limit of infinite U or zero temperature. Near the SDW instability we find approximately marginal Fermi-liquid behavior, a pseudogap in the density of states, and a singlet d(x)2(-gamma)2 pairing instability. Below T-c, gaps open rapidly in the frequency spectra of the gap function, the quasiparticle scattering rate, and the density of states. The spectral density of the dynamic spin susceptibility agrees qualitatively with the neutron-scattering data on La2-xSrxCuO4. The quasiparticle scattering rate and spin-lattice relaxation rate T-1(-1) decrease rapidly below T-c. The photoemission intensities along the antinode and node of the gap are in good agreement with the angle-resolved photoemission spectroscopy data on Bi 2212. Including next-nearest-neighbor hopping we obtain for sufficiently large coupling (U/t greater than or similar to 7) a broad commensurate neutron-scattering peak like the observed one in YBa2Cu3O6+x.