Stability of the Dirac cone in artificial graphene formed in quantum wells : A computational many-electron study

Abstract

We carry out a comprehensive computational study on the stability of the Dirac cone in artificial graphene realized in nanopatterned quantum wells. Our real-space approach allows us to vary the size, shape, and positioning of the quantum dots in the hexagonal lattice. We compare the (noninteracting) single-particle calculations to density-functional studies within both local-density approximation and meta-generalized-gradient approximation. Furthermore, the density-functional results are compared against numerically precise path-integral quantum Monte Carlo calculations. As a whole, our results indicate high stability of the Dirac bands against external parameters, which is reassuring for further experimental investigations.