Doping-dependent evolution of the electronic structure of La2-xSrxCuO4 in the superconducting and metallic phases

C. Kim, M. Nakamura, T. Yoshida, T. Mizokawa, A. Fujimori, Z. X. Shen, T. Kakeshita, H. Eisaki, S. Uchida, A. Ino


309 被引用数 (Scopus)


The electronic structure of the La2-xSrxCuO4 (LSCO) system has been studied by angle-resolved photo-emission spectroscopy (ARPES). We report on the evolution of the Fermi surface, the superconducting gap, and the band dispersion around the extended saddle point k = (π,0) with hole doping in the superconducting and metallic phases. As hole concentration x decreases, the flat band at (π,0) moves from above the Fermi level (EF) for x>0.2 to below EF for x<0.2, and is further lowered down to x = 0.05. From the leading-edge shift of ARPES spectra, the magnitude of the superconducting gap around (π,0) is found to monotonically increase as x decreases from x = 0.30 down to x = 0.05 even though Tc decreases in the underdoped region, and the superconducting gap appears to smoothly evolve into the normal-state gap at x = 0.05. It is shown that the energy scales characterizing these low-energy structures have similar doping dependences. For the heavily overdoped sample (x = 0.30), the band dispersion and the ARPES spectral line shape are analyzed using a simple phenomenological self-energy form, and the electronic effective mass enhancement factor m*/mb≃2 has been found. As the hole concentration decreases, an incoherent component that cannot be described within the simple self-energy analysis grows intense in the high-energy tail of the ARPES peak. Some unusual features of the electronic structure observed for the underdoped region (x≤0.10) are consistent with numerical works on the stripe model.

ジャーナルPhysical Review B - Condensed Matter and Materials Physics
出版ステータスPublished - 2002 3 1

ASJC Scopus subject areas

  • 電子材料、光学材料、および磁性材料
  • 凝縮系物理学


「Doping-dependent evolution of the electronic structure of La<sub>2-x</sub>Sr<sub>x</sub>CuO<sub>4</sub> in the superconducting and metallic phases」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。