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arXiv · 1002.2630

Doping-dependent nodal Fermi velocity in Bi-2212 revealed by high-resolution ARPES

I. M. Vishik·W. S. Lee·F. Schmitt·B. Moritz·T. Sasagawa·S. Uchida·K. Fujita·S. Ishida·C. Zhang·T. P. Devereaux·Z. -X. Shen
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Abstract

The improved resolution of laser-based angle-resolved photoemission spectroscopy (ARPES) allows reliable access to fine structures in the spectrum. We present a systematic, doping-dependent study of a recently discovered low-energy kink in the nodal dispersion of Bi2Sr2CaCu2O8+d (Bi-2212), which demonstrates the ubiquity and robustness of this kink in underdoped Bi-2212. The renormalization of the nodal velocity due to this kink becomes stronger with underdoping, revealing that the nodal Fermi velocity is non-universal, in contrast to assumed phenomenology. This is used together with laser-ARPES measurements of the gap velocity, v2, to resolve discrepancies with thermal conductivity measurements.

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I. M. Vishik, W. S. Lee, F. Schmitt, B. Moritz, T. Sasagawa, S. Uchida, K. Fujita, S. Ishida, C. Zhang, T. P. Devereaux, Z. -X. Shen. 2010-03-22. Doping-dependent nodal Fermi velocity in Bi-2212 revealed by high-resolution ARPES. https://doi.org/10.1103/physrevlett.104.207002

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