paper

Effects of next-nearest-neighbor hopping $t^{'}$ on the electronic structure of cuprates

arXiv:cond-mat/0312575 · doi:10.1103/PhysRevB.70.092503

Abstract

Photoemission spectra of underdoped and lightly-doped Bi $_{2 - z}$ Pb $_{z}$ Sr $_{2}$ Ca $_{1 - x}$ {\it R} $_{x}$ Cu $_{2}$ O $_{8 + y}$ ( $R =$ Pr, Er) (BSCCO) have been measured and compared with those of La $_{2 - x}$ Sr $_{x}$ CuO $_{4}$ (LSCO). The lower-Hubbard band of the insulating BSCCO, like Ca $_{2}$ CuO $_{2}$ Cl $_{2}$ , shows a stronger dispersion than La $_{2}$ CuO $_{4}$ from $k \sim$ ( $I ¨ /2, I ¨ /2$ ) to $\sim$ ( $I ¨ , 0$ ). The flat band at $k \sim$ ( $I ¨ , 0$ ) 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.

5 pages,4 figures, 1 table

Effects of next-nearest-neighbor hopping t′ on the electronic structure of cuprates

Abstract

Effects of next-nearest-neighbor hopping $t^{'}$ on the electronic structure of cuprates