Chemical potential shift in lightly doped to overdoped Bi2Sr2Ca1-xRxCu2O8+y(R = Pr, Er) -: art. no. 172501

We have studied the chemical potential shift in the high-temperature superconductor Bi2Sr2Ca1-xRxCu2O8+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 is depressed in the underdoped region as in the case of La2-xSrxCuO4 (LSCO) but the depression 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.