Strongly interacting Hofstadter states in magic-angle twisted bilayer graphene
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arXiv
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| Auteurs principaux: | , , , , , , , , , , |
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| Format: | Preprint |
| Publié: |
2024
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| _version_ | 1866916910310883328 |
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| author | He, Minhao Wang, Xiaoyu Cai, Jiaqi Herzog-Arbeitman, Jonah Taniguchi, Takashi Watanabe, Kenji Stern, Ady Bernevig, B. Andrei Yankowitz, Matthew Vafek, Oskar Xu, Xiaodong |
| author_facet | He, Minhao Wang, Xiaoyu Cai, Jiaqi Herzog-Arbeitman, Jonah Taniguchi, Takashi Watanabe, Kenji Stern, Ady Bernevig, B. Andrei Yankowitz, Matthew Vafek, Oskar Xu, Xiaodong |
| contents | Magic-angle twisted bilayer graphene (MATBG) hosts a multitude of strongly correlated states at partial fillings of its flat bands. In a magnetic field, these flat bands further evolve into a unique Hofstadter spectrum renormalized by strong Coulomb interactions. Here, we study the interacting Hofstadter states spontaneously formed within the topological magnetic subbands of an ultraclean MATBG device, notably including symmetry-broken Chern insulator (SBCI) states and fractional quantum Hall (FQH) states. The observed SBCI states form a cascade with their Chern numbers mimicking the main sequence correlated Chern insulators. The FQH states in MATBG form in Jain sequence; however, they disappear at high magnetic field, distinct from conventional FQH states which strengthen with increasing magnetic field. We reveal a unique magnetic field-driven phase transition from composite fermion phases to a dissipative Fermi liquid. Our theoretical analysis of the magnetic subbands hosting FQH states predicts non uniform quantum geometric properties far from the lowest Landau level. This points towards a more natural interpretation of these FQH states as in-field fractional Chern insulators of the magnetic subbands. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2408_01599 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Strongly interacting Hofstadter states in magic-angle twisted bilayer graphene He, Minhao Wang, Xiaoyu Cai, Jiaqi Herzog-Arbeitman, Jonah Taniguchi, Takashi Watanabe, Kenji Stern, Ady Bernevig, B. Andrei Yankowitz, Matthew Vafek, Oskar Xu, Xiaodong Mesoscale and Nanoscale Physics Strongly Correlated Electrons Magic-angle twisted bilayer graphene (MATBG) hosts a multitude of strongly correlated states at partial fillings of its flat bands. In a magnetic field, these flat bands further evolve into a unique Hofstadter spectrum renormalized by strong Coulomb interactions. Here, we study the interacting Hofstadter states spontaneously formed within the topological magnetic subbands of an ultraclean MATBG device, notably including symmetry-broken Chern insulator (SBCI) states and fractional quantum Hall (FQH) states. The observed SBCI states form a cascade with their Chern numbers mimicking the main sequence correlated Chern insulators. The FQH states in MATBG form in Jain sequence; however, they disappear at high magnetic field, distinct from conventional FQH states which strengthen with increasing magnetic field. We reveal a unique magnetic field-driven phase transition from composite fermion phases to a dissipative Fermi liquid. Our theoretical analysis of the magnetic subbands hosting FQH states predicts non uniform quantum geometric properties far from the lowest Landau level. This points towards a more natural interpretation of these FQH states as in-field fractional Chern insulators of the magnetic subbands. |
| title | Strongly interacting Hofstadter states in magic-angle twisted bilayer graphene |
| topic | Mesoscale and Nanoscale Physics Strongly Correlated Electrons |
| url | https://arxiv.org/abs/2408.01599 |