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The superconducting gap in the Hubbard model and the two gap energy scales in high-Tc cuprates

M. Aichhorn·E. Arrigoni·Z. B. Huang·W. Hanke
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Abstract

Recent excperiments (ARPES, Raman) suggest the presence of two distinct energy gaps in high-Tc superconductors (HTSC), exhibiting different doping dependences. Results of a variational cluster approach to the superconducting state of the two-dimensional Hubbard model are presented which show that this model qualitatively describes this gap dichotomy: One gap (antinodal) increases with less doping, a behavior long considered as reflecting the general gap behavior of the HTSC. On the other hand, the near-nodal gap does even slightly decrease with underdoping. An explanation of this unexpected behavior is given which emphasizes the crucial role of spin fluctuations in the pairing mechanism.

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M. Aichhorn, E. Arrigoni, Z. B. Huang, W. Hanke. 2007-09-28. The superconducting gap in the Hubbard model and the two gap energy scales in high-Tc cuprates. https://doi.org/10.1103/physrevlett.99.257002

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