Correlation Effects in a Simplified Bilayer Two-Orbital Hubbard Model at Half Filling
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arXiv
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| Auteurs principaux: | , , |
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| Format: | Preprint |
| Publié: |
2024
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| _version_ | 1866913680460873728 |
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| author | Yang, Jian-Jian Yao, Dao-Xin Wu, Han-Qing |
| author_facet | Yang, Jian-Jian Yao, Dao-Xin Wu, Han-Qing |
| contents | Motivated by the discovery of high-temperature superconductivity in bilayer nickelate La$_3$Ni$_2$O$_7$ under pressure, we investigate the ground-state phase diagram and correlation effects using determinant quantum Monte Carlo simulations in a simplified bilayer two-orbital Hubbard model at half filling. Our results reveal the emergence of a nonmagnetic weakly insulating phase at weak on-site Hubbard interactions, transitioning to an antiferromagnetic Mott insulating phase as the interaction strength exceeds a critical value $U/t_1^x\approx 4.15$. This phase transition is consistent with the 3D O(3) Heisenberg universality class. Additionally, we analyze dynamical properties such as the single-particle spectral function and dynamic spin structure factor. The pronounced inter-layer correlation of $d_{3z^2-r^2}$ orbitals results in a downward trend and an extended flatness in the $γ$ band, mirroring the angle-resolved photoemission spectroscopy findings under ambient pressure. Our numerical results provide important clues for understanding the strong correlation effects in La$_3$Ni$_2$O$_7$. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2408_12042 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Correlation Effects in a Simplified Bilayer Two-Orbital Hubbard Model at Half Filling Yang, Jian-Jian Yao, Dao-Xin Wu, Han-Qing Strongly Correlated Electrons Motivated by the discovery of high-temperature superconductivity in bilayer nickelate La$_3$Ni$_2$O$_7$ under pressure, we investigate the ground-state phase diagram and correlation effects using determinant quantum Monte Carlo simulations in a simplified bilayer two-orbital Hubbard model at half filling. Our results reveal the emergence of a nonmagnetic weakly insulating phase at weak on-site Hubbard interactions, transitioning to an antiferromagnetic Mott insulating phase as the interaction strength exceeds a critical value $U/t_1^x\approx 4.15$. This phase transition is consistent with the 3D O(3) Heisenberg universality class. Additionally, we analyze dynamical properties such as the single-particle spectral function and dynamic spin structure factor. The pronounced inter-layer correlation of $d_{3z^2-r^2}$ orbitals results in a downward trend and an extended flatness in the $γ$ band, mirroring the angle-resolved photoemission spectroscopy findings under ambient pressure. Our numerical results provide important clues for understanding the strong correlation effects in La$_3$Ni$_2$O$_7$. |
| title | Correlation Effects in a Simplified Bilayer Two-Orbital Hubbard Model at Half Filling |
| topic | Strongly Correlated Electrons |
| url | https://arxiv.org/abs/2408.12042 |