Artificial Graphene in Nano-patterned GaAs Quantum Wells

ORAL

Abstract

We report the realization of artificial graphene (AG) in a 2D electron gas in a highly tunable semiconductor quantum well system. Very short period (as small as 40 nm) honeycomb lattices were formed in a GaAs heterostructure by electron beam lithography followed by dry etching. Characterization of the AG samples by photoluminescence at low temperature (about 4K) indicates modulation of 2D electron states. Low-lying electron excitations observed by resonant inelastic light scattering and interpreted with a calculated AG band structure confirm the formation of AG bands with a well-defined Dirac cone, evidence for the presence of massless Dirac fermions. These results suggest that engineered semiconductor nano-scale structures can serve as advanced quantum simulators for probing novel electron behavior in low dimensional systems.

*Supported by DOE-BES Award DE-SC0010695

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Authors

  • Sheng Wang

    • Department of Applied Physics, Columbia University

  • Diego Scarabelli

    • Department of Applied Physics, Columbia University

  • Yuliya Y. Kuznetsova

    • Department of Physics, Columbia University

  • Loren Pfeiffer

    • Princeton University
    • Dept. of Electrical Engineering, Princeton University, Princeton, NJ
    • Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544
    • Department of Electrical Engineering, Princeton University
    • Princeton

  • Ken West

    • Department of Electrical Engineering, Princeton University

  • Geoff C. Gardner

    • Purdue University Birck Nanotechnology Center
    • Purdue University
    • Department of Physics and Astronomy, and School of Materials Engineering, and School of Electrical and Computer Engineering, Purdue University

  • Michael Manfra

    • Purdue University Dept. of Physics
    • Purdue University
    • Department of Physics and Astronomy, and School of Materials Engineering, and School of Electrical and Computer Engineering, Purdue University

  • Vittorio Pellegrini

    • Italian Institute of Technology
    • Istituto Italiano di Tecnologia, Graphene Labs, Genova, Italy and NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Pisa, Italy

  • Shalom J. Wind

    • Columbia University
    • Department of Applied Physics, Columbia University

  • Aron Pinczuk

    • Columbia University
    • Department of Physics and Department of Applied Physics, Columbia University