Academic Journal
Topological Lifshitz transitions, orbital currents, and interactions in low-dimensional Fermi gases in synthetic gauge fields
| العنوان: | Topological Lifshitz transitions, orbital currents, and interactions in low-dimensional Fermi gases in synthetic gauge fields |
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| المؤلفون: | Chen-How Huang, Masaki Tezuka, Miguel A Cazalilla |
| المصدر: | New Journal of Physics, Vol 24, Iss 3, p 033043 (2022) |
| بيانات النشر: | IOP Publishing |
| سنة النشر: | 2022 |
| المجموعة: | Directory of Open Access Journals: DOAJ Articles |
| مصطلحات موضوعية: | fermions in optical lattices, synthetic gauge fields, orbital currents, strongly correlated fermions, Tomonaga–Luttinger liquids, mean-field theories, Science, Physics, QC1-999 |
| الوصف: | Low-dimensional systems of interacting fermions in a synthetic gauge field have been experimentally realized using two-component ultra-cold Fermi gases in optical lattices. Using a two-leg ladder model that is relevant to these experiments, we have studied the signatures of topological Lifshitz transitions and the effects of the inter-species interaction U on the gauge-invariant orbital current in the regime of large intra-leg hopping Ω. Focusing on non-insulating regimes, we have carried out numerically exact density-matrix renormalization-group (DMRG) calculations to compute the orbital current at fixed particle number as a function of the interaction strength and the synthetic gauge flux per plaquette. Signatures of topological Lifshitz transitions where the number Fermi points changes are found to persist even in the presence of very strong repulsive interactions. This numerical observation suggests that the orbital current can be computed from an appropriately renormalized mean-field band structure, which is also described here. Quantitative agreement between the mean-field and the DMRG results in the intermediate interaction regime where U ≲ Ω is demonstrated. We also have observed that interactions can change the sign of the current susceptibility at zero field and induce Lifshitz transitions between two metallic phases, which is also captured by the mean-field theory. Correlation effects beyond mean-field theory in the oscillations of the local inter-leg current are also reported. We argue that the observed robustness against interactions makes the orbital current a good indicator of the topological Lifshitz transitions. |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| تدمد: | 1367-2630 |
| Relation: | https://doi.org/10.1088/1367-2630/ac5a87; https://doaj.org/toc/1367-2630; https://doaj.org/article/9ef853424e944eaba01dc9c79e3b1347 |
| DOI: | 10.1088/1367-2630/ac5a87 |
| الاتاحة: | https://doi.org/10.1088/1367-2630/ac5a87 https://doaj.org/article/9ef853424e944eaba01dc9c79e3b1347 |
| رقم الانضمام: | edsbas.FEDF5E04 |
| قاعدة البيانات: | BASE |
Full Text Finder | تدمد: | 13672630 |
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| DOI: | 10.1088/1367-2630/ac5a87 |