Pseudogaps in strongly correlated metals: A generalized dynamical mean-field theory approach
Pseudogaps in strongly correlated metals: A generalized dynamical mean-field theory approach
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强相关金属中的赝能隙：广义动态平均场理论方法
DOI：
10.1103/physrevb.72.155105
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发表时间：
2005
影响因子：
3.7
通讯作者：
V. Anisimov
中科院分区：
文献类型：
--
作者：
M. V. Sadovskii;I. Nekrasov;É. Z. Kuchinskii;T. Pruschke;V. Anisimov
我们推广的动态平均场DMFT近似的DMFT方程包括一些长度尺度通过依赖于动量的外部自能k。这种外部自能描述了由短程集体自旋密度波状反铁磁自旋或电荷密度波状电荷涨落引起的非局域动力学关联。在足够高的温度下，这些波动可以被看作是一个有限相关长度的淬火高斯随机场。这种广义的DMFT+k方法被用于数值解的弱掺杂的单带Hubbard模型与排斥库仑相互作用的正方形晶格上的最近和次近邻跳跃。利用数值重整化群求解了广义DMFT+k中的有效单杂质问题。这两种类型的强相关金属，即：i的掺杂莫特绝缘体和ii的情况下的本地库仑相互作用的带宽WU U值被认为是。的态密度，光谱函数，和角分辨的光电子能谱计算内的DMFT+k显示赝能隙附近的费米能级的准粒子带形成。
We generalize the dynamical-mean field DMFT approximation by including into the DMFT equations some length scale via a momentum dependent external self-energy k. This external self-energy describes nonlocal dynamical correlations induced by the short-ranged collective spin density wave‐like antiferromagnetic spin or the charge density wave‐like charge fluctuations. At high enough temperatures these fluctuations can be viewed as a quenched Gaussian random field with a finite correlation length. This generalized DMFT+k approach is used for the numerical solution of the weakly doped one-band Hubbard model with repulsive Coulomb interaction on a square lattice with the nearest and the next nearest neighbor hopping. The effective single impurity problem in this generalized DMFT+k is solved by the numerical renormalization group. Both types of the strongly correlated metals, namely: i The doped Mott insulator and ii the case of the bandwidth WU U—value of the local Coulomb interaction are considered. The densities of states, the spectral functions, and the angle resolved photoemission spectra calculated within the DMFT+k show a pseudogap formation near the Fermi level of the quasiparticle band.