Sénéchal David, Tremblay A-M S
Département de Physique and Regroupement Québécois sur les Matériaux de Pointe, Université de Sherbrooke, Sherbrooke, Québec, Canada.
Phys Rev Lett. 2004 Mar 26;92(12):126401. doi: 10.1103/PhysRevLett.92.126401. Epub 2004 Mar 22.
Using cluster perturbation theory, it is shown that the spectral weight and pseudogap observed at the Fermi energy in recent angle resolved photoemission spectroscopy of both electron- and hole-doped high-temperature superconductors find their natural explanation within the t-t(')-t(")-U Hubbard model in two dimensions. The value of the interaction U needed to explain the experiments for electron-doped systems at optimal doping is in the weak to intermediate coupling regime where the t-J model is inappropriate. At strong coupling, short-range correlations suffice to create a pseudogap, but at weak-coupling long correlation lengths associated with the antiferromagnetic wave vector are necessary.
利用团簇微扰理论表明，在电子掺杂和空穴掺杂高温超导体的近期角分辨光电子能谱中，在费米能处观测到的光谱权重和赝能隙，在二维的t - t（'）- t（"）- U哈伯德模型中有其合理的解释。对于最佳掺杂的电子掺杂系统，解释实验所需的相互作用U值处于弱耦合到中间耦合区域，在该区域t - J模型并不适用。在强耦合时，短程关联足以产生赝能隙，但在弱耦合时，与反铁磁波矢相关的长关联长度是必要的。
