Ferromagnetic diagonal stripe states in the two-dimensional Hubbard model with U

• Published in: Physics letters. A 2022-09, Vol.446, p.128276, Article 128276
• Main Authors: Miyazaki, Mitake, Yanagisawa, Takashi
• Format: Article
• Language: English
• Subjects: Ferromagnetism; Hubbard model; Stripe states; Strongly correlated electron system; Variational Monte Carlo method
• ISSN: 0375-9601; 1873-2429
• DOI: 10.1016/j.physleta.2022.128276

We have performed a variational Monte Carlo simulation to study the ground state of a two-dimensional Hubbard model on a square lattice in the strong coupling region. The energy gain of possible inhomogeneous electron states are computed as a function of U when the hole density ϵ=1/8 and next nearest-neighbor hopping t′/t=−0.30. The bond-centered ferromagnetic diagonal stripe state is stabilized in the strong coupling region (U/t≥16), which is due to the gain of both kinetic energy and on-site Coulomb interaction energy due to the holon moving over the ferromagnetic domain and the gain of kinetic-exchange-interaction energy at the antiferromagnetic domain wall. •This article applied the variational Monte Carlo method to investigate the ground state of two-dimensional square lattice Hubbard model with U≲∞.•At 1/8 doping, a ferromagnetic diagonal stripe state consisting of a ferromagnetic domain and an antiferromagnetic domain wall is found to be stable in the U/t≥16 region.•In the strongly correlated region, the ferromagnetic stripe state has a large kinetic energy gain of holes compared to the uniform electronic state.•The spatial distribution of the staggered magnetization, the charge density, and the double occupation number in the ferromagnetic diagonal stripe state is shown.