Effects of next-nearest-neighbor hopping t′ on the electronic structure of cuprate superconductors
Effects of next-nearest-neighbor hopping t′ on the electronic structure of cuprate superconductors
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DOI：
10.1103/physrevb.70.092503
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发表时间：
2004-09-01
影响因子：
3.7
通讯作者：
Terasaki, I
中科院分区：
文献类型：
--
作者：
Tanaka, K;Yoshida, T;Terasaki, I
测量了低掺杂和轻掺杂Bi2-zPbzSr2Ca1-xRxCu2O8+y(R=Pr，Er)(BSCCO)的光电子能谱，并与La2-xSrxCuO4(LSCO)的光电子能谱进行了比较。绝缘BSCCO的下Hubbard带，如Ca2CuO2Cl2，表现出比La2CuO4更强的弥散，从k类似于(pi/2，pi/2)到类似于(pi，0)。与(pi，0)相似的平带一般在BSCCO中较深。这些观测结合费米面形状和化学势移动表明，BSCCO单带模型的次近邻跃迁t(‘)大于LSCO模型，并且影响赝隙能级的不是超交换J，而是t(’)。
Photoemission spectra of underdoped and lightly-doped Bi2-zPbzSr2Ca1-xRxCu2O8+y (R=Pr, Er) (BSCCO) have been measured and compared with those of La2-xSrxCuO4 (LSCO). The lower-Hubbard band of the insulating BSCCO, like Ca2CuO2Cl2, shows a stronger dispersion than La2CuO4 from ksimilar to(pi/2,pi/2) to similar to(pi,0). The flat band at ksimilar to(pi,0) is found generally deeper in BSCCO. These observations together with the Fermi-surface shapes and the chemical potential shifts indicate that the next-nearest-neighbor hopping \t(')\ of the single-band model is larger in BSCCO than in LSCO and that \t(')\ rather than the super-exchange J influences the pseudogap energy scale.