Atomic resolution imaging of the two-component Dirac-Landau levels in a gapped graphene monolayer
Atomic resolution imaging of the two-component Dirac-Landau levels in a gapped graphene monolayer
复制标题
带隙石墨烯单层中双组分狄拉克-朗道能级的原子分辨率成像
DOI：
10.1103/physrevb.92.165420
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发表时间：
2015
影响因子：
3.7
通讯作者：
L. He
中科院分区：
文献类型：
--
作者：
W. X. Wang;L. J. Yin;J. B. Qiao;T. C. Cai;S. Y. Li;R. F. Dou;J. C. Nie;X. S. Wu;L. He
The wavefunction of massless Dirac fermions is a two-component spinor. In graphene, a one-atom-thick film showing two-dimensional Dirac-like electronic excitations, the two-component representation reflects the amplitude of the electron wavefunction on the A and B sublattices. This unique property provides unprecedented opportunities to image the two components of massless Dirac fermions spatially. Here we report atomic resolution imaging of the two-component Dirac-Landau levels in a gapped graphene monolayer by scanning tunnelling microscopy and spectroscopy. A gap of about 20 meV, driven by inversion symmetry breaking by the substrate potential, is observed in the graphene on both SiC and graphite substrates. Such a gap splits the n = 0 Landau level (LL) into two levels, 0+ and 0-. We demonstrate that the amplitude of the wavefunction of the 0- LL is mainly at the A sites and that of the 0+ LL is mainly at the B sites of graphene, characterizing the internal structure of the spinor of the n = 0 LL. This provides direct evidence of the two-component nature of massless Dirac fermions.
