تقرير
Emergent ferromagnetism near three-quarters filling in twisted bilayer graphene
| العنوان: | Emergent ferromagnetism near three-quarters filling in twisted bilayer graphene |
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| المؤلفون: | Sharpe, Aaron L., Fox, Eli J., Barnard, Arthur W., Finney, Joe, Watanabe, Kenji, Taniguchi, Takashi, Kastner, M. A., Goldhaber-Gordon, David |
| المصدر: | Science 365, 605-608 (2019) |
| سنة النشر: | 2019 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Strongly Correlated Electrons |
| الوصف: | When two sheets of graphene are stacked at a small twist angle, the resulting flat superlattice minibands are expected to strongly enhance electron-electron interactions. Here we present evidence that near three-quarters ($3/4$) filling of the conduction miniband these enhanced interactions drive the twisted bilayer graphene into a ferromagnetic state. We observe emergent ferromagnetic hysteresis, with a giant anomalous Hall (AH) effect as large as $10.4\ \mathrm{k\Omega}$ and signs of chiral edge states in a narrow density range around an apparent insulating state at $3/4$. Surprisingly, the magnetization of the sample can be reversed by applying a small DC current. Although the AH resistance is not quantized and dissipation is significant, we suggest that the system is an incipient Chern insulator. Comment: 18 pages, 4 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1126/science.aaw3780 |
| URL الوصول: | http://arxiv.org/abs/1901.03520 |
| رقم الأكسشن: | edsarx.1901.03520 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1126/science.aaw3780 |
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