Reconstruction of the Bi2Sr2CaCu2O8+δ Fermi surface

• Published in: Physical review. B 2019-12, Vol.100 (24), p.1
• Main Authors: Valla, T, Pletikosić, I, Drozdov, I K, Gu, G D
• Format: Article
• Language: English
• Subjects: Banded structure; Electronic structure; Electrons; Fermi surfaces; Hybridization; Photoelectric emission; Reconstruction
• ISSN: 2469-9950; 2469-9969
• DOI: 10.1103/PhysRevB.100.241112

The effects of structural supermodulation with the period λ ≈ 26 Å along the b axis of Bi2Sr2CaCu2O8+δ have been observed in photoemission studies from the early days as the presence of "diffraction replicas" of the intrinsic electronic structure. Although predicted to affect the electronic structure of the Cu-O plane, the influence of supermodulation potential on Cu-O electrons has never been observed in photoemission. In the present study, we clearly see the effects on the Bi2Sr2CaCu2O8+δ electronic structure; we observe a hybridization of the intrinsic bands with the supermodulation replica bands in the form of avoided crossings and a corresponding reconstruction of the Fermi surface. We estimate the hybridization gap, 2Δh ∼ 25 meV, in the slightly underdoped samples. The hybridization weakens with doping and the anticrossing can no longer be resolved in strongly overdoped samples. In contrast, the "shadow" replica, shifted by ( π , π ) , is found not to hybridize with the original bands within our detection limits.