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arXiv · 1102.1911

Superconductivity and Pairing Fluctuations in the Half-Filled Two-Dimensional Hubbard Model

Michael Sentef·Philipp Werner·Emanuel Gull·Arno P. Kampf
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Abstract

The two-dimensional Hubbard model exhibits superconductivity with d-wave symmetry even at half-filling in the presence of next-nearest neighbor hopping. Using plaquette cluster dynamical mean-field theory with a continuous-time quantum Monte Carlo impurity solver, we reveal the non-Fermi liquid character of the metallic phase in proximity to the superconducting state. Specifically, the low-frequency scattering rate for momenta near (\pi, 0) varies non-monotonously at low temperatures, and the dc conductivity is T-linear at elevated temperatures with an upturn upon cooling. Evidence is provided that pairing fluctuations dominate the normal-conducting state even considerably above the superconducting transition temperature.

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Michael Sentef, Philipp Werner, Emanuel Gull, Arno P. Kampf. 2011-02-09. Superconductivity and Pairing Fluctuations in the Half-Filled Two-Dimensional Hubbard Model. https://doi.org/10.1103/physrevlett.107.126401

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