2015/12/31 by Jose Gonzalez, J. González, Rafael A. Molina · 32 citations
Materials Science · Physics and Astronomy · #Angular momentum #Band gap #Condensed matter physics #Dirac (video compression format) #Floquet theory #Graphene research and applications #Physics #Quantization (signal processing) #Quantum Mechanics and Non-Hermitian Physics #Quantum electrodynamics #Quantum mechanics #Radiation #Semimetal #Surface (topology) #Surface states #Topological Materials and Phenomena #Zero mode #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevlett.116.156803
published in Physical Review Letters 116(15), 156803 (American Physical Society) · 5 pages + supplemental material
openalex publication_date 2016/04/15 · arxiv created 2016/05/13 · arxiv updated 2016/05/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate the development of novel surface states when 3D Dirac or Weyl semimetals are placed under circularly polarized electromagnetic radiation. We find that the hybridization between inverted Floquet bands opens, in general, a gap, which closes at so-called exceptional points found for complex values of the momentum. This corresponds to the appearance of midgap surface states in the form of evanescent waves decaying from the surface exposed to the radiation. We observe a phenomenon reminiscent of Landau quantization by which the midgap surface states get a large degeneracy proportional to the radiation flux traversing the surface of the semimetal. We show that all of these surface states carry angular current, leading to an angular modulation of their charge that rotates with the same frequency of the radiation, which should manifest in the observation of a macroscopic chiral current in the irradiated surface.