Artificial Graphene in Nano-patterned Triangular Antidot Lattices on GaAs Heterostructures

Artificial graphene (AG) in semiconductors have recently been realized in honeycomb quantum dot lattices superimposed on a GaAs quantum well [1], serving as quantum simulators for probing novel electron behavior. Here we report the realization of AG in nano-patterned triangular antidot lattices on the GaAs quantum well [2]. Using cutting-edge fabrication technology we created small-period triangular antidot lattices reaching periods as small as 70 nm (equivalent to 40nm in a honeycomb lattice). The electron states were explored by resonant inelastic light scattering (RILS) at low temperature. Massless Dirac Fermions (MDF) are clearly revealed in RILS spectra due to low-lying transitions between AG bands and in spectra due to combined intersubband transitions. Control of the created MDF through tuning the antidot potential will be discussed. [1] S. Wang, et al., Nature Nanotechnology accepted for publication. [2] L. Du, et al., in preparation.