Artificial lattices in nano-patterned GaAs Heterostructure*

Artificial lattices in semiconductors have been realized with honeycomb lattices superimposed on 2D electron systems in GaAs quantum well to serve as advanced quantum simulators for probing novel electron behavior in low dimensional systems. Here, we report on recent experimental progresses in artificial lattice studies using the cutting-edge fabrication technology and exploration of created electron states by optical spectroscopy experiments using photoluminescence and resonant inelastic light scattering at low temperature. Very short period (as small as 40 nm) honeycomb lattices realize massless Dirac-fermions in a highly tunable GaAs quantum well system. We also explore the triangular antidot lattice, where Dirac fermions occur at larger period. Control over carrier density and Fermi level to tune massless Dirac fermions, and the realization of topological insulator states in artificial lattices will be discussed.