Two-dimensional Mott-Hubbard electrons in an artificial honeycomb lattice

Abstract

Electrons in artificial lattices enable explorations of the impact of repulsive Coulomb interactions in a tunable system. We have trapped two-dimensional electrons belonging to a gallium arsenide quantum well in a nanofabricated lattice with honeycomb geometry. We probe the excitation spectrum in a magnetic field identifying novel collective modes that emerge from the Coulomb interaction in the artificial lattice as predicted by the Mott-Hubbard model. These observations allow us to determine the Hubbard gap and suggest the existence of a novel Coulomb-driven ground state. This approach offers new venues for the study of quantum phenomena in a controllable solid-state system.

10 pages, 10 figures

References in corpus (13)

• Many-Body Physics with Ultracold Gases
• Ultracold atomic gases in optical lattices: mimicking condensed matter physics and beyond
• Quantum Hall Ferromagnetism in Graphene
• Landau Level Splitting in Graphene in High Magnetic Fields
• Topological Mott Insulators
• Spin Filtered Edge States and Quantum Hall Effect in Graphene
• The zero-energy state in graphene in a high magnetic field
• Graphene integer quantum Hall effect in the ferromagnetic and paramagnetic regimes
• Engineering artificial graphene in a two-dimensional electron gas
• Excitonic gap, phase transition, and quantum Hall effect in graphene
• Making Massless Dirac Fermions from Patterned Two-Dimensional Electron Gases
• Quantum simulation of Fermi-Hubbard models in semiconductor quantum dot arrays
• A molecular state of correlated electrons in a quantum dot