2024/07/18 by Ren-He Xu, Hantao Lu, Xu, Ren-He +5
Physics and Astronomy · #Advanced Chemical Physics Studies #FOS: Physical sciences #Physics of Superconductivity and Magnetism #Quantum many-body systems #Strongly Correlated Electrons (cond-mat.str-el)
paper · pdf · doi:10.48550/arxiv.2407.13136
openalex publication_date 2024/07/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
By utilizing the twisted boundary conditions in the exact diagonalization method, we investigate the single-particle spectral function of the extended Peierls-Hubbard model at both half-filling and quarter filling. In one-dimensional (1D) interacting systems, the spin-charge separation can typically be identified in the single-particle spectral function by observing the distinct spinon and holon bands. At half filling, starting from the pure 1D Hubbard model with the on-site interaction U=10, we observe that the band structure indicative of the spin-charge separation gradually transitions to four individual bands as the Peierls instability δ increases. At U=10 and δ=0.2 where the spin-charge separation is still observable, increasing the nearest-neighbor interaction V can drive the system to a charge-density-wave (CDW) state when V\gtrsim U/2, without the obeservation of spinon and holon bands. At quarter-filling, on the other hand, the ground state of Peierls-Hubbard model manifests an antiferromagnetic Mott insulator in units of dimers. Increasing U results in only a very small gap in the single-particle spectrum because even for U=+∞, with the model transforming into a noninteracting half-filled dimerized tight-binding model, its gap determined by the Peierls instability δ remains small. Conversely, increasing V can effectively open the single-particle gap and make the spinon and holon bands more prominent.