Chemical potential shift in Nd2-xCexCuO4:: Contrasting behavior between the electron- and hole-doped cuprates -: art. no. 220507

We have studied the chemical potential shift in the electron-doped superconductor Nd2-xCexCuO4 by precise measurements of core-level photoemission spectra. The result shows that the chemical potential monotonously increases with electron doping, quite differently from La2-xSrxCuO4, where the shift is suppressed in the underdoped region. If the suppression of the shift in La2-xSrxCuO4 is attributed to strong stripe fluctuations, the monotonous increase of the chemical potential is consistent with the absence of stripe fluctuations in Nd2-xCexCuO4. The chemical potential jump between Nd2CuO4 and La2CuO4 is suggested to be much smaller than the optical band gaps.