Magnetotransport study of the mini-Dirac cone in AB-stacked four- to six-layer graphene under perpendicular electric field
| Autor: | Tomoaki Nakasuga, Kota Horii, Ryoya Ebisuoka, Takashi Taniguchi, Kenji Watanabe, Taiki Hirahara, Shingo Tajima, Ryuta Yagi |
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| Rok vydání: | 2019 |
| Předmět: |
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FOS: Physical sciences 02 engineering and technology Condensed Matter - Soft Condensed Matter 01 natural sciences Asymmetry law.invention law Electric field Dispersion relation 0103 physical sciences Mesoscale and Nanoscale Physics (cond-mat.mes-hall) Perpendicular 010306 general physics media_common Physics Condensed Matter - Materials Science Condensed Matter - Mesoscale and Nanoscale Physics Condensed matter physics Graphene Degenerate energy levels Materials Science (cond-mat.mtrl-sci) Landau quantization 021001 nanoscience & nanotechnology Magnetic field Soft Condensed Matter (cond-mat.soft) 0210 nano-technology |
| DOI: | 10.48550/arxiv.1906.06853 |
| Popis: | Landau levels of AB-stacked four- to six-layer graphene were studied experimentally in the presence of a perpendicular electric field. The Landau levels at a low magnetic field showed a characteristic structure that originated from the mini-Dirac cones created by the perpendicular electric fields. Six-fold or twelve-fold degenerate Landau levels arising from the mini-Dirac cones were observed in the vicinity of the charge neutrality point as a radial structure in a plot of their Landau fan diagrams. The structure of four-layer graphene had approximate electron-hole symmetry near the charge neutrality point, while the five- and six-layer graphene showed asymmetry. Numerical calculations of the dispersion relation and Landau level spectra indicated that trigonal warping played an essential role in forming the experimentally observed Landau level structure in low magnetic fields. In high magnetic fields, trigonal warping becomes less significant and the Landau level spectra become simpler, approaching those that were calculated without considering trigonal warping. The appearance of mini-Dirac cones in a perpendicular electric field would be a common feature of AB-stacked multilayer graphene. |
| Databáze: | OpenAIRE |
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