By means of first-principles calculations, we predict a partially hydrogenated graphene system, ${\mathrm{C}}_6{\mathrm{H}}_2$, and find the one in $AB$-trans configuration is a Dirac material with a tilted anisotropic Dirac cone electronic structure. Different from graphene, in which the Dirac points are located at $K$ and $K^{\prime }$ and the Fermi surfaces are circular with doping, the $AB$-trans ${\mathrm{C}}_6{\mathrm{H}}_2$ exhibits Dirac points located on the lines from $\mathrm{\Gamma }$ to $M$ with quasielliptical Fermi surfaces when doped. Around the Dirac point, the Fermi velocity varies along different directions. Therefore, the propagation of charge carriers in this system is highly anisotropic, creating a new tunability for novel transport properties.

• Received 24 May 2016
• Revised 27 October 2016

DOI:https://doi.org/10.1103/PhysRevB.94.195423