Exciton band topology in spontaneous quantum anomalous Hall insulators: applications to twisted bilayer graphene
We uncover topological features of neutral particle-hole pair excitations of correlated quantum anomalous Hall (QAH) insulators whose approximately flat conduction and valence bands have equal and opposite nonzero Chern number. Using an exactly solvable model we show that the underlying band topolog...
| Main Authors: | , , , |
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| Format: | Journal article |
| Language: | English |
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American Physical Society
2021
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| _version_ | 1797090332554297344 |
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| author | Kwan, YH Hu, Y Simon, SH Parameswaran, SA |
| author_facet | Kwan, YH Hu, Y Simon, SH Parameswaran, SA |
| author_sort | Kwan, YH |
| collection | OXFORD |
| description | We uncover topological features of neutral particle-hole pair excitations of correlated quantum anomalous Hall (QAH) insulators whose approximately flat conduction and valence bands have equal and opposite nonzero Chern number. Using an exactly solvable model we show that the underlying band topology affects both the center-of-mass and relative motion of particle-hole bound states. This leads to the formation of topological exciton bands whose features are robust to nonuniformity of both the dispersion and the Berry curvature. We apply these ideas to recently reported broken-symmetry spontaneous QAH insulators in substrate aligned magic-angle twisted bilayer graphene. |
| first_indexed | 2024-03-07T03:17:03Z |
| format | Journal article |
| id | oxford-uuid:b624f9a7-0f4f-4f41-af57-b88a73e552a4 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T03:17:03Z |
| publishDate | 2021 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | oxford-uuid:b624f9a7-0f4f-4f41-af57-b88a73e552a42022-03-27T04:38:55ZExciton band topology in spontaneous quantum anomalous Hall insulators: applications to twisted bilayer grapheneJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:b624f9a7-0f4f-4f41-af57-b88a73e552a4EnglishSymplectic ElementsAmerican Physical Society2021Kwan, YHHu, YSimon, SHParameswaran, SAWe uncover topological features of neutral particle-hole pair excitations of correlated quantum anomalous Hall (QAH) insulators whose approximately flat conduction and valence bands have equal and opposite nonzero Chern number. Using an exactly solvable model we show that the underlying band topology affects both the center-of-mass and relative motion of particle-hole bound states. This leads to the formation of topological exciton bands whose features are robust to nonuniformity of both the dispersion and the Berry curvature. We apply these ideas to recently reported broken-symmetry spontaneous QAH insulators in substrate aligned magic-angle twisted bilayer graphene. |
| spellingShingle | Kwan, YH Hu, Y Simon, SH Parameswaran, SA Exciton band topology in spontaneous quantum anomalous Hall insulators: applications to twisted bilayer graphene |
| title | Exciton band topology in spontaneous quantum anomalous Hall insulators: applications to twisted bilayer graphene |
| title_full | Exciton band topology in spontaneous quantum anomalous Hall insulators: applications to twisted bilayer graphene |
| title_fullStr | Exciton band topology in spontaneous quantum anomalous Hall insulators: applications to twisted bilayer graphene |
| title_full_unstemmed | Exciton band topology in spontaneous quantum anomalous Hall insulators: applications to twisted bilayer graphene |
| title_short | Exciton band topology in spontaneous quantum anomalous Hall insulators: applications to twisted bilayer graphene |
| title_sort | exciton band topology in spontaneous quantum anomalous hall insulators applications to twisted bilayer graphene |
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