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arXiv · 0810.0292

Spectroscopic evidence for preformed Cooper pairs in the pseudogap phase of cuprates

M. Shi·A. Bendounan·E. Razzoli·S. Rosenkranz·M. R. Norman·J. C. Campuzano·J. Chang·M. Mansson·Y. Sassa·T. Claesson·O. Tjernberg·L. Patthey·N. Momono·M. Oda·M. Ido·S. Guerrero·C. Mudry·J. Mesot
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Abstract

Angle-resolved photoemission on underdoped La$_{1.895}$Sr$_{0.105}$CuO$_4$ reveals that in the pseudogap phase, the dispersion has two branches located above and below the Fermi level with a minimum at the Fermi momentum. This is characteristic of the Bogoliubov dispersion in the superconducting state. We also observe that the superconducting and pseudogaps have the same d-wave form with the same amplitude. Our observations provide direct evidence for preformed Cooper pairs, implying that the pseudogap phase is a precursor to superconductivity.

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M. Shi, A. Bendounan, E. Razzoli, S. Rosenkranz, M. R. Norman, J. C. Campuzano, J. Chang, M. Mansson, Y. Sassa, T. Claesson, O. Tjernberg, L. Patthey, N. Momono, M. Oda, M. Ido, S. Guerrero, C. Mudry, J. Mesot. 2008-10-01. Spectroscopic evidence for preformed Cooper pairs in the pseudogap phase of cuprates. https://doi.org/10.1209/0295-5075/88/27008

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