Dirac electrons in a dodecagonal graphene quasicrystal

作者：Ahn, Sung Joon; Moon, Pilkyung; Kim, Tae-Hoon; Kim, Hyun-Woo; Shin, Ha-Chul; Kim, Eun Hye; Cha, Hyun Woo; Kahng, Se-Jong; Kim, Philip; Koshino, Mikito; Son, Young-Woo^*; Yang, Cheol-Woong^*; Ahn, Joung Real^*

来源：Science, 2018, 361(6404): 782-+.

DOI：10.1126/science.aar8412

• TWISTED BILAYER GRAPHENE
• BAND-STRUCTURE
• TRANSPORT
• LATTICE
• STATES
• SYMMETRY
• PHASE
• LAYER

Quantum states of quasiparticles in solids are dictated by symmetry. We have experimentally demonstrated quantum states of Dirac electrons in a two-dimensional quasicrystal without translational symmetry. A dodecagonal quasicrystalline order was realized by epitaxial growth of twisted bilayer graphene rotated exactly 30 degrees. We grew the graphene quasicrystal up to a millimeter scale on a silicon carbide surface while maintaining the single rotation angle over an entire sample and successfully isolated the quasicrystal from a substrate, demonstrating its structural and chemical stability under ambient conditions. Multiple Dirac cones replicated with the 12-fold rotational symmetry were observed in angle-resolved photoemission spectra, which revealed anomalous strong interlayer coupling with quasi-periodicity. Our study provides a way to explore physical properties of relativistic fermions with controllable quasicrystalline orders.

• 出版日期2018-8-24
• 单位华东师范大学