Bulk currents in artificial graphene with a magnetic field

Full text: We present calculations of the equilibrium current density for a patterned 2DEG with infinite strip geometry and a perpendicular magnetic field. A triangular lattice of anti-dots with lattice spacing 120 nm and potential maximum close to or above to Fermi level. Such a system is known as artificial graphene (AG). To compute the current density we numerically diagonalize the AG Hamiltonian over a set of Landau level basis states, this takes into account coupling between different Landau levels. Our calculations show that, at fields typical for quantum Hall measurements, the bulk current as two distinct components. One component is due to localized electrons in closed orbits around each anti-dot and scales weakly with potential modulation. The presence of a second component is the focus of this work. We show that there exist a set of extended streams of current which flow through the entire sample. These streams scale roughly in proportion to the potential strength and carry a current comparable to that carried by edge modes. (author)