Valley-chiral quantum Hall state in graphene superlattice structureH. Y. Tian, W. W. Tao, J. Wang, Y. H. Cui, N. Xu, B. B. Huang, G. X. Luo and Y. H. HaoEPL, 114 4 (2016) 47003DOI: https://doi.org/10.1209/0295-5075/114/47003