1998/06/25 by F. F. Assaad, Assaad, F. F.
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Iron-based superconductors research #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con) #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.cond-mat/9806306
4 pages including 6 figures in encapsulated postscript format
arxiv created 1998/06/25 · openalex publication_date 1998/06/25 · arxiv updated 2009/11/30 · openalex created_date 2022/10/12 · openalex updated_date 2026/07/28
We consider the repulsive Hubbard model on a square lattice with an additional term, W, which depends upon the square of a single-particle nearest-neighbor hopping. At half-band filling, constant W, we show that enhancing U/t drives the system from a d-wave superconductor to an antiferromagnetic Mott insulator. At zero temperature in the superconducting phase, spin-spin correlations follow a powerlaw: exp(-i r Q) |r|^(-alpha). Here Q = (pi, pi) and alpha is in the range 1 < alpha < 2 and depends upon the coupling constants W and U. This results is reached on the basis of large scale quantum Monte-Carlo simulations on lattices up to 24 times 24, and is shown to be independent on the choice of the boundary conditions. We define a pairing (magnetic) scale by the temperature below which short range d-wave pairing correlations (antiferromagnetic fluctuations) start growing. With finite temperature quantum Monte Carlo simulations, we demonstrate that both scales are identical over a large energy range. Those results show the extreme compatibility and close interplay of antiferromagnetic fluctuations and d-wave superconductivity.