2014/01/02 by Tim O. Wehling, T.O. Wehling, T. O. Wehling +6 · 981 citations
Materials Science · Physics and Astronomy · #2D Materials and Applications #Condensed matter physics #Dirac (video compression format) #Dirac fermion #Dirac sea #Fermion #Fermion doubling #Graphene #Graphene research and applications #Helical Dirac fermion #Physics #Quantum mechanics #Topological Materials and Phenomena #Topological insulator #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1080/00018732.2014.927109
published in Advances In Physics 63(1), 1-76 (Taylor & Francis) · Review article accepted in Adv. Phys. 77 pages
openalex publication_date 2014/01/02 · arxiv created 2014/05/22 · arxiv updated 2014/08/27 · openalex created_date 2020/07/02 · openalex updated_date 2026/08/05
A wide range of materials, like d-wave superconductors, graphene, and topological insulators, share a fundamental similarity: their low-energy fermionic excitations behave as massless Dirac particles rather than fermions obeying the usual Schrödinger Hamiltonian. This emergent behavior of Dirac fermions in condensed matter systems defines the unifying framework for a class of materials we call “Dirac materials.” In order to establish this class of materials, we illustrate how Dirac fermions emerge in multiple entirely different condensed matter systems and we discuss how Dirac fermions have been identified experimentally using electron spectroscopy techniques (angle-resolved photoemission spectroscopy and scanning tunneling spectroscopy). As a consequence of their common low-energy excitations, this diverse set of materials shares a significant number of universal properties in the low-energy (infrared) limit. We review these common properties including nodal points in the excitation spectrum, density of states, specific heat, transport, thermodynamic properties, impurity resonances, and magnetic field responses, as well as discuss many-body interaction effects. We further review how the emergence of Dirac excitations is controlled by specific symmetries of the material, such as time-reversal, gauge, and spin–orbit symmetries, and how by breaking these symmetries a finite Dirac mass is generated. We give examples of how the interaction of Dirac fermions with their distinct real material background leads to rich novel physics with common fingerprints such as the suppression of back scattering and impurity-induced resonant states.