Observation of Dirac bands in artificial graphene in small-period nanopatterned GaAs quantum wells

Sheng Wang, Diego Scarabelli, Lingjie Du, Yuliya Y. Kuznetsova, Loren N. Pfeiffer, Ken W. West, Geoff C. Gardner, Michael J. Manfra, Vittorio Pellegrini, Shalom J. Wind, Aron Pinczuk

Research output: Contribution to journalArticlepeer-review

51 Scopus citations


Charge carriers in graphene behave like massless Dirac fermions (MDFs) with linear energy-momentum dispersion 1, 2, providing a condensed-matter platform for studying quasiparticles with relativistic-like features. Artificial graphene (AG) - a structure with an artificial honeycomb lattice - exhibits novel phenomena due to the tunable interplay between topology and quasiparticle interactions 3-6 . So far, the emergence of a Dirac band structure supporting MDFs has been observed in AG using molecular 5, atomic 6, 7 and photonic systems 8-10, including those with semiconductor microcavities 11 . Here, we report the realization of an AG that has a band structure with vanishing density of states consistent with the presence of MDFs. This observation is enabled by a very small lattice constant (a = 50 nm) of the nanofabricated AG patterns superimposed on a two-dimensional electron gas hosted by a high-quality GaAs quantum well. Resonant inelastic light-scattering spectra reveal low-lying transitions that are not present in the unpatterned GaAs quantum well. These excitations reveal the energy dependence of the joint density of states for AG band transitions. Fermi level tuning through the Dirac point results in a collapse of the density of states at low transition energy, suggesting the emergence of the MDF linear dispersion in the AG.

Original languageEnglish (US)
Pages (from-to)29-33
Number of pages5
JournalNature Nanotechnology
Issue number1
StatePublished - Jan 1 2018
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Bioengineering
  • Atomic and Molecular Physics, and Optics
  • Biomedical Engineering
  • General Materials Science
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


Dive into the research topics of 'Observation of Dirac bands in artificial graphene in small-period nanopatterned GaAs quantum wells'. Together they form a unique fingerprint.

Cite this