Direct observation of photonic Landau levels and helical edge states in strained honeycomb lattices

Omar Jamadi, Elena Rozas, Grazia Salerno, Marijana Milićević, Tomoki Ozawa, Isabelle Sagnes, Aristide Lemaître, Luc Le Gratiet, Abdelmounaim Harouri, Iacopo Carusotto, Jacqueline Bloch, Alberto Amo

Research output: Contribution to journalArticlepeer-review

24 Citations (Scopus)


We report the realization of a synthetic magnetic field for photons and polaritons in a honeycomb lattice of coupled semiconductor micropillars. A strong synthetic field is induced in both the s and p orbital bands by engineering a uniaxial hopping gradient in the lattice, giving rise to the formation of Landau levels at the Dirac points. We provide direct evidence of the sublattice symmetry breaking of the lowest-order Landau level wavefunction, a distinctive feature of synthetic magnetic fields. Our realization implements helical edge states in the gap between n = 0 and n = ±1 Landau levels, experimentally demonstrating a novel way of engineering propagating edge states in photonic lattices. In light of recent advances in the enhancement of polariton–polariton nonlinearities, the Landau levels reported here are promising for the study of the interplay between pseudomagnetism and interactions in a photonic system.

Original languageEnglish
Article number144
JournalLight: Science and Applications
Issue number1
Publication statusPublished - 2020 Dec 1
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics


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