A New Anisotropic Dirac Cone Material: A B 2 S Honeycomb Monolayer

• Published in: The journal of physical chemistry letters Vol. 9; no. 7; pp. 1815 - 1820
• Main Authors: Zhao, Yu, Li, Xiaoyin, Liu, Junyi, Zhang, Cunzhi, Wang, Qian
• Format: Journal Article
• Language: English
• Published: United States 05.04.2018
• ISSN: 1948-7185; 1948-7185
• DOI: 10.1021/acs.jpclett.8b00616

Different from the isotropic Dirac cones existing in other 2D materials, anisotropic Dirac cones have a merit of anisotropic carrier mobility for applications in direction-dependent quantum devices. Motivated by the recent experimental finding of anisotropic Dirac cone in borophene (Adv. Mater. 2018, 30, 1704025), here we report a new 2D anisotropic Dirac cone material, B2S monolayer, identified by using global structure search method and first principles calculation combined with tight-binding model. The B2S monolayer is found to be stable mechanically, thermally and dynamically, and exhibits an anisotropic Dirac cone exactly at the Fermi level, showing a Fermi-velocity of 106 m/s in the same order of magnitude as that of graphene. Moreover, B2S monolayer is the first anisotropy Dirac cone material with a prisitne honeycomb structure stabilized by S in free standing condition where each atom has four valence electrons on average being isoelectronic to C. This study would expand Dirac cone materials family with new features.