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arXiv · 1001.0102

Chemical potential jump between hole- and electron-doped sides of ambipolar high-Tc cuprate

M. Ikeda·M. Takizawa·T. Yoshida·A. Fujimori·Kouji Segawa·Yoichi Ando
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Abstract

In order to study an intrinsic chemical potential jump between the hole- and electron-doped high-Tc superconductors, we have performed core-level X-ray photoemission spectroscopy (XPS) measurements of Y0.38La0.62Ba1.74La0.26Cu3Oy (YLBLCO), into which one can dope both holes and electrons with maintaining the same crystal structure. Unlike the case between the hole-doped system La_2-xSrxCuO4 and the electron-doped system Nd_2-xCexCuO4, we have estimated the true chemical potential jump between the hole- and electron-doped YLBLCO to be ~0.8 eV, which is much smaller than the optical gaps of 1.4-1.7 eV reported for the parent insulating compounds. We attribute the reduced jump to the indirect nature of the charge-excitation gap as well as to the polaronic nature of the doped carriers.

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M. Ikeda, M. Takizawa, T. Yoshida, A. Fujimori, Kouji Segawa, Yoichi Ando. 2009-12-31. Chemical potential jump between hole- and electron-doped sides of ambipolar high-Tc cuprate. https://doi.org/10.1103/physrevb.82.020503

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