Eta-pairing state in flatband lattice: Interband coupling effect on entanglement entropy logarithm
Fuente:
arXiv
Enregistré dans:
| Auteurs principaux: | , , , , , |
|---|---|
| Format: | Preprint |
| Publié: |
2025
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1866916707216392192 |
|---|---|
| author | Pak, Seik Kim, Hanbyul Bark, Chan Bin Sin, Sang-Jin Choi, Jae-yoon Park, Moon Jip |
| author_facet | Pak, Seik Kim, Hanbyul Bark, Chan Bin Sin, Sang-Jin Choi, Jae-yoon Park, Moon Jip |
| contents | The eta-pairing state is the eigenstate of the hypercubic Hubbard model, which exhibits anomalous logarithmic scaling of entanglement entropy. In multi-band systems, eta-pairing can be exact eigenstate when the band is flat without interband coupling. However, typical flatband systems such as Lieb and Kagome lattices often feature band touchings, where interband coupling effects are non-negligible. Using the Creutz ladder, we investigate the deformation of eta-pairing states under the interband coupling effect. Our results show corrections to entanglement entropy scaling, with modified eta-pairing states displaying broadened doublons, nonuniform energy spacing, and deviations from exact behavior for configurations with more than one eta-pair, even in the large band gap limit, except at t = 0. Through a Schrieffer-Wolff transformation, we quantify corrections to the spectrum generating algebra, offering insights into the interplay between interaction-driven phenomena and band structure effects. These findings illuminate the robustness and limitations of eta-pairing in realistic flatband systems. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2504_17845 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Eta-pairing state in flatband lattice: Interband coupling effect on entanglement entropy logarithm Pak, Seik Kim, Hanbyul Bark, Chan Bin Sin, Sang-Jin Choi, Jae-yoon Park, Moon Jip Strongly Correlated Electrons Quantum Physics The eta-pairing state is the eigenstate of the hypercubic Hubbard model, which exhibits anomalous logarithmic scaling of entanglement entropy. In multi-band systems, eta-pairing can be exact eigenstate when the band is flat without interband coupling. However, typical flatband systems such as Lieb and Kagome lattices often feature band touchings, where interband coupling effects are non-negligible. Using the Creutz ladder, we investigate the deformation of eta-pairing states under the interband coupling effect. Our results show corrections to entanglement entropy scaling, with modified eta-pairing states displaying broadened doublons, nonuniform energy spacing, and deviations from exact behavior for configurations with more than one eta-pair, even in the large band gap limit, except at t = 0. Through a Schrieffer-Wolff transformation, we quantify corrections to the spectrum generating algebra, offering insights into the interplay between interaction-driven phenomena and band structure effects. These findings illuminate the robustness and limitations of eta-pairing in realistic flatband systems. |
| title | Eta-pairing state in flatband lattice: Interband coupling effect on entanglement entropy logarithm |
| topic | Strongly Correlated Electrons Quantum Physics |
| url | https://arxiv.org/abs/2504.17845 |