| Autor: |
Lu, Xiaobo, Tang, Jian, Wallbank, John R., Wang, Shuopei, Shen, Cheng, Wu, Shuang, Chen, Peng, Yang, Wei, Zhang, Jing, Watanabe, Kenji, Taniguchi, Takashi, Yang, Rong, Shi, Dongxia, Efetov, Dmitri K., Falko, Vladimir I., Zhang, Guangyu |
| Rok vydání: |
2020 |
| Předmět: |
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| Zdroj: |
Phys. Rev. B 102, 045409,2020 |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1103/PhysRevB.102.045409 |
| Popis: |
The propagation of Dirac fermions in graphene through a long-period periodic potential would result in a band folding together with the emergence of a series of cloned Dirac points (DPs). In highly aligned graphene/hexagonal boron nitride (G/hBN) heterostructures, the lattice mismatch between the two atomic crystals generates a unique kind of periodic structure known as a moir\'e superlattice. Of particular interests is the emergent phenomena related to the reconstructed band-structure of graphene, such as the Hofstadter butterfly, topological currents, gate dependent pseudospin mixing, and ballistic miniband conduction. However, most studies so far have been limited to the lower-order minibands, e.g. the 1st and 2nd minibands counted from charge neutrality, and consequently the fundamental nature of the reconstructed higher-order miniband spectra still remains largely unknown. Here we report on probing the higher-order minibands of precisely aligned graphene moir\'e superlattices by transport spectroscopy. Using dual electrostatic gating, the edges of these high-order minibands, i.e. the 3rd and 4th minibands, can be reached. Interestingly, we have observed interband Landau level (LL) crossinginducing gap closures in a multiband magneto-transport regime, which originates from band overlap between the 2nd and 3rd minibands. As observed high-order minibands and LL reconstruction qualitatively match our simulated results. Our findings highlight the synergistic effect of minibands in transport, thus presenting a new opportunity for graphene electronic devices. |
| Databáze: |
arXiv |
| Externí odkaz: |
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