2024/07/15 by Chao Zhang, Zhang, Chao
Physics and Astronomy · #Atomic and Subatomic Physics Research #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #Quantum, superfluid, helium dynamics #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con)
paper · pdf · doi:10.48550/arxiv.2407.10444
openalex publication_date 2024/07/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Using numerically exact diagrammatic Monte Carlo simulations in the two-electron (single-bipolaron) sector, we explore the impact of long-range Coulomb repulsion on the dilute-limit Berezinskii--Kosterlitz--Thouless (BKT) transition temperature Tc of bipolarons on a two-dimensional square lattice. We study the bond Su--Schrieffer--Heeger model, in which bond phonons modulate the electron hopping. In the absence of long-range repulsion, this model was shown to support small, light bipolarons with a comparatively high transition temperature \citePhysRevX.13.011010. Here we find that long-range Coulomb repulsion suppresses the optimal Tc but leaves it appreciable over a broad parameter window, including the adiabatic regime ω/t=0.5 at a representative Coulomb strength V=U/10 (with U the on-site repulsion). Our results provide controlled single-bipolaron inputs for dilute-limit Tc estimates in the presence of long-range repulsion.