Proximity-induced nodal metal in an extremely underdoped CuO₂ plane in triple-layer cuprates.

ABSTRACT: We performed angle-resolved photoemission spectroscopy studies on the triple-layer Bi₂Sr₂Ca₂Cu₃O_10+δ over a wide doping range. Although the doping level of the inner CuO₂ plane is extremely low in underdoped samples, the d-wave SC gap is enhanced to the unprecedentedly large value of Δ₀ ~ 80-100 meV at the antinode. This gap persists well above T_c without a Fermi arc, indicating a "nodal metal". We attribute the nodal metallic behavior to the unique local environment of the inner clean CuO₂ plane, sandwiched by nearly optimally-doped two outer planes and hence subject to strong proximity effect from both sides. In the nodal metal, quasiparticle peaks show electron-hole symmetry, suggesting d-

SUBMITTER: Ideta SI 

PROVIDER: S-EPMC12559703 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature