2025/01/09 by Rayan Farid, Farid, Rayan, Daria Gazizova +5 · 1 citation
Materials Science · Medicine · Physics and Astronomy · #Advanced MRI Techniques and Applications #Atomic and Subatomic Physics Research #FOS: Physical sciences #Magnetism in coordination complexes #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con)
paper · pdf · doi:10.48550/arxiv.2501.04915
openalex publication_date 2025/01/09 · openalex created_date 2025/01/11 · openalex updated_date 2026/07/28
We study the two-dimensional extended Hubbard model on a square lattice and incorporate spin-differentiated nearest neighbor (NN) interactions where the equal-spin (Vuu) and unequal-spin (Vud) terms are independently tuned parameters. We compute single-particle excitations as well as static spin and pairing susceptibilities perturbatively up to the fourth order within the thermodynamic limit and at a finite fixed temperature. By explicitly encoding a ferromagnetic-like NN interaction (Vuu < Vud), we induce a competition among the uniform q = (0,0), collinear q = (π,0), and staggered q = (π,π) spin excitations. This results in the formation of short-ranged 2× 2 ferromagnetic plaquettes arranged in staggered or striped patterns. Kinetic frustration in hopping, both within and between these plaquettes, manifests in single-particle properties, resulting in a reduction of bandwidth and ultimately triggering a Lifshitz transition to quasi-one-dimensional bands. Furthermore, an attractive effective interaction within the localized ferromagnetic plaquette results in the emergence of equal-spin triplet p-wave pairing. We demonstrate that sufficiently strong magnetic fluctuations, even at finite length scales, can significantly influence single-particle and pairing properties without breaking translational symmetry. Our approach provides a novel pathway to realize a variety of rich magnetic phases and Fermi surface reconstruction driven by interactions in the absence of explicit geometric frustration.