Antiferromagnetically ordered Mott insulator and $d+id$ superconductivity in twisted bilayer graphene: A quantum Monte carlo study
| Autor: | Huang, Tongyun, Zhang, Lufeng, Ma, Tianxing |
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| Rok vydání: | 2018 |
| Předmět: | |
| Zdroj: | Science Bulletin, 2019, 64(5):310-314 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1016/j.scib.2019.01.026 |
| Popis: | Using exact quantum Monte Carlo method, we examine the recent novel electronic states seen in magic-angle graphene superlattices. From the Hubbard model on a double-layer honeycomb lattice with a rotation angle $\theta=1.08^{\circ}$, we reveal that an antiferromagnetically ordered Mott insulator emerges beyond a critical $U_c$ at half filling, and with a small doping, the pairing with $d+id$ symmetry dominates over other pairings at low temperature. The effective $d+id$ pairing interaction strongly increase as the on-site Coulomb interaction increases, indicating that the superconductivity is driven by electron-electron correlation. Our non-biased numerical results demonstrate that the twisted bilayer graphene share the similar superconducting mechanism of high temperature superconductors, which is a new and idea platform for further investigating the strongly correlated phenomena. Comment: 6 pages, 7 figures. A very careful revision on finite-size scaling analysis and sign problem are made, and some more references are added |
| Databáze: | arXiv |
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