Mobile spin impurity in an optical lattice
We investigate the Fermi polaron problem in a spin-1/2 Fermi gas in an optical lattice for the limit of both strong repulsive contact interactions and one dimension. In this limit, a polaronic-like behaviour is not expected, and the physics is that of a magnon or impurity. While the charge degrees o...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2017-01-01
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| Series: | New Journal of Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1367-2630/aa753e |
| _version_ | 1797750603086036992 |
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| author | C W Duncan F F Bellotti P Öhberg N T Zinner M Valiente |
| author_facet | C W Duncan F F Bellotti P Öhberg N T Zinner M Valiente |
| author_sort | C W Duncan |
| collection | DOAJ |
| description | We investigate the Fermi polaron problem in a spin-1/2 Fermi gas in an optical lattice for the limit of both strong repulsive contact interactions and one dimension. In this limit, a polaronic-like behaviour is not expected, and the physics is that of a magnon or impurity. While the charge degrees of freedom of the system are frozen, the resulting tight-binding Hamiltonian for the impurity’s spin exhibits an intriguing structure that strongly depends on the filling factor of the lattice potential. This filling dependency also transfers to the nature of the interactions for the case of two magnons and the important spin balanced case. At low filling, and up until near unit filling, the single impurity Hamiltonian faithfully reproduces a single-band, quasi-homogeneous tight-binding problem. As the filling is increased and the second band of the single particle spectrum of the periodic potential is progressively filled, the impurity Hamiltonian, at low energies, describes a single particle trapped in a multi-well potential. Interestingly, once the first two bands are fully filled, the impurity Hamiltonian is a near-perfect realisation of the Su–Schrieffer–Heeger model. Our studies, which go well beyond the single-band approximation, that is, the Hubbard model, pave the way for the realisation of interacting one-dimensional models of condensed matter physics. |
| first_indexed | 2024-03-12T16:35:12Z |
| format | Article |
| id | doaj.art-263d27a2c5d545aa85ebc99d5b8b2c82 |
| institution | Directory Open Access Journal |
| issn | 1367-2630 |
| language | English |
| last_indexed | 2024-03-12T16:35:12Z |
| publishDate | 2017-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | New Journal of Physics |
| spelling | doaj.art-263d27a2c5d545aa85ebc99d5b8b2c822023-08-08T14:53:26ZengIOP PublishingNew Journal of Physics1367-26302017-01-0119707500110.1088/1367-2630/aa753eMobile spin impurity in an optical latticeC W Duncan0F F Bellotti1P Öhberg2N T Zinner3M Valiente4SUPA, Institute of Photonics and Quantum Sciences, Heriot-Watt University , Edinburgh EH14 4AS, United KingdomDepartment of Physics & Astronomy, Aarhus University , Ny Munkegade 120, DK-8000 Aarhus C, DenmarkSUPA, Institute of Photonics and Quantum Sciences, Heriot-Watt University , Edinburgh EH14 4AS, United KingdomDepartment of Physics & Astronomy, Aarhus University , Ny Munkegade 120, DK-8000 Aarhus C, DenmarkSUPA, Institute of Photonics and Quantum Sciences, Heriot-Watt University , Edinburgh EH14 4AS, United KingdomWe investigate the Fermi polaron problem in a spin-1/2 Fermi gas in an optical lattice for the limit of both strong repulsive contact interactions and one dimension. In this limit, a polaronic-like behaviour is not expected, and the physics is that of a magnon or impurity. While the charge degrees of freedom of the system are frozen, the resulting tight-binding Hamiltonian for the impurity’s spin exhibits an intriguing structure that strongly depends on the filling factor of the lattice potential. This filling dependency also transfers to the nature of the interactions for the case of two magnons and the important spin balanced case. At low filling, and up until near unit filling, the single impurity Hamiltonian faithfully reproduces a single-band, quasi-homogeneous tight-binding problem. As the filling is increased and the second band of the single particle spectrum of the periodic potential is progressively filled, the impurity Hamiltonian, at low energies, describes a single particle trapped in a multi-well potential. Interestingly, once the first two bands are fully filled, the impurity Hamiltonian is a near-perfect realisation of the Su–Schrieffer–Heeger model. Our studies, which go well beyond the single-band approximation, that is, the Hubbard model, pave the way for the realisation of interacting one-dimensional models of condensed matter physics.https://doi.org/10.1088/1367-2630/aa753estrong interactionsoptical latticeone dimensionimpurity |
| spellingShingle | C W Duncan F F Bellotti P Öhberg N T Zinner M Valiente Mobile spin impurity in an optical lattice New Journal of Physics strong interactions optical lattice one dimension impurity |
| title | Mobile spin impurity in an optical lattice |
| title_full | Mobile spin impurity in an optical lattice |
| title_fullStr | Mobile spin impurity in an optical lattice |
| title_full_unstemmed | Mobile spin impurity in an optical lattice |
| title_short | Mobile spin impurity in an optical lattice |
| title_sort | mobile spin impurity in an optical lattice |
| topic | strong interactions optical lattice one dimension impurity |
| url | https://doi.org/10.1088/1367-2630/aa753e |
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