Fully Gapped Single-Particle Excitations in the Lightly Doped Cuprates

K. M. Shen; T. Yoshida; D. H. Lu; F. Ronning; N. P. Armitage; W. S. Lee; X. J. Zhou; A. Damascelli; D. L. Feng; N. J. C. Ingle; H. Eisaki; Y. Kohsaka; H. Takagi; T. Kakeshita; S. Uchida; P. K. Mang; M. Greven; Y. Onose; Y. Taguchi; Y. Tokura; Seiki Komiya; Yoichi Ando; M. Azuma; M. Takano; A. Fujimori; Z. -X. Shen

doi:10.1103/physrevb.69.054503

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Fully Gapped Single-Particle Excitations in the Lightly Doped Cuprates

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Abstract

The low-energy excitations of the lightly doped cuprates were studied by angle-resolved photoemission spectroscopy. A finite gap was measured over the entire Brillouin zone, including along the d_{x^2 - y^2} nodal line. This effect was observed to be generic to the normal states of numerous cuprates, including hole-doped La_{2-x}Sr_{x}CuO_{4} and Ca_{2-x}Na_{x}CuO_{2}Cl_{2} and electron-doped Nd_{2-x}Ce_{x}CuO_{4}. In all compounds, the gap appears to close with increasing carrier doping. We consider various scenarios to explain our results, including the possible effects of chemical disorder, electronic inhomogeneity, and a competing phase.

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K. M. Shen, T. Yoshida, D. H. Lu, F. Ronning, N. P. Armitage, W. S. Lee, X. J. Zhou, A. Damascelli, D. L. Feng, N. J. C. Ingle, H. Eisaki, Y. Kohsaka, H. Takagi, T. Kakeshita, S. Uchida, P. K. Mang, M. Greven, Y. Onose, Y. Taguchi, Y. Tokura, Seiki Komiya, Yoichi Ando, M. Azuma, M. Takano, A. Fujimori, Z. -X. Shen. 2003-12-11. Fully Gapped Single-Particle Excitations in the Lightly Doped Cuprates. https://doi.org/10.1103/physrevb.69.054503

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