Experimental Evidence of Chiral Symmetry Breaking in Kekulé-Ordered Graphene.

  title={Experimental Evidence of Chiral Symmetry Breaking in Kekul{\'e}-Ordered Graphene.},
  author={Changhua Bao and Hongyun Zhang and Teng Zhang and Xi Wu and Laipeng Luo and Shaohua Zhou and Qian Li and Yanhui Hou and Wei Yao and Liwei Liu and Pu Yu and Jia Li and Wenhui Duan and Hong Yao and Yeliang Wang and Shuyun Zhou},
  journal={Physical review letters},
  volume={126 20},
The low-energy excitations of graphene are relativistic massless Dirac fermions with opposite chiralities at valleys K and K^{'}. Breaking the chiral symmetry could lead to gap opening in analogy to dynamical mass generation in particle physics. Here we report direct experimental evidences of chiral symmetry breaking (CSB) from both microscopic and spectroscopic measurements in a Li-intercalated graphene. The CSB is evidenced by gap opening at the Dirac point, Kekulé-O type modulation, and… Expand

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