Chemical potential shift in lightly-doped to overdoped Bi₂Sr₂Ca₁₋ₓ RₓCu₂O₈₊y (R = Pr, Er)

الأصل · EN

We have studied the chemical potential shift in the high-temperature superconductor Bi₂Sr₂Ca₁₋ₓ RₓCu₂O₈₊y (R = Pr, Er), where the hole concentration is varied from 0.025 to 0.17 per Cu, by precise measurements of core-level photoemission spectra. The result shows that the shift becomes slow in the underdoped region as in the case of La₂₋ₓSrₓCuO₄ (LSCO) but the effect is much weaker than in LSCO. The observed shift in the present system can be relatively well explained by numerical results on the doped two-dimensional Hubbard model, and suggests that the change of the electronic structure induced by hole doping is less influenced by stripe fluctuations than in LSCO.