Exact and mean-field analysis of the role of Hubbard interactions on flux driven circular current in a quantum ring
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arXiv
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| Autores principales: | , , |
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| Formato: | Preprint |
| Publicado: |
2025
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| _version_ | 1866917518506983424 |
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| author | Samanta, Rahul Maiti, Santanu K. Sil, Shreekantha |
| author_facet | Samanta, Rahul Maiti, Santanu K. Sil, Shreekantha |
| contents | We investigate circular current in both ordered and disordered Hubbard quantum rings threaded by magnetic flux, employing exact diagonalization and the Hartree-Fock mean-field approach within the tight-binding framework. The influence of on-site and extended Hubbard interactions, disorder, and electron filling on the persistent current is systematically analyzed. To construct the full many-body Hamiltonian, we introduce a linear table formalism, which, to our knowledge, has been rarely used in this context. In ordered rings, the current decreases monotonically with increasing on-site repulsion, while the impact of the extended interaction depends strongly on the filling factor. At low filling, stronger extended interaction suppresses the current, whereas near half-filling, it enhances the current up to a critical ratio, half of the on-site strength, before reducing it. Disorder significantly modifies these behaviors, notably enhancing the current at less than quarter-filling with increasing extended interaction. The localization properties of eigenstates, examined via the inverse participation ratio, further support the crucial roles of filling and the interplay between on-site and extended interactions in governing persistent current. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2512_04736 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Exact and mean-field analysis of the role of Hubbard interactions on flux driven circular current in a quantum ring Samanta, Rahul Maiti, Santanu K. Sil, Shreekantha Mesoscale and Nanoscale Physics Disordered Systems and Neural Networks Strongly Correlated Electrons We investigate circular current in both ordered and disordered Hubbard quantum rings threaded by magnetic flux, employing exact diagonalization and the Hartree-Fock mean-field approach within the tight-binding framework. The influence of on-site and extended Hubbard interactions, disorder, and electron filling on the persistent current is systematically analyzed. To construct the full many-body Hamiltonian, we introduce a linear table formalism, which, to our knowledge, has been rarely used in this context. In ordered rings, the current decreases monotonically with increasing on-site repulsion, while the impact of the extended interaction depends strongly on the filling factor. At low filling, stronger extended interaction suppresses the current, whereas near half-filling, it enhances the current up to a critical ratio, half of the on-site strength, before reducing it. Disorder significantly modifies these behaviors, notably enhancing the current at less than quarter-filling with increasing extended interaction. The localization properties of eigenstates, examined via the inverse participation ratio, further support the crucial roles of filling and the interplay between on-site and extended interactions in governing persistent current. |
| title | Exact and mean-field analysis of the role of Hubbard interactions on flux driven circular current in a quantum ring |
| topic | Mesoscale and Nanoscale Physics Disordered Systems and Neural Networks Strongly Correlated Electrons |
| url | https://arxiv.org/abs/2512.04736 |