Dirac materials

By T. Wehling, A. Black‐Schaffer, Alexander V. Balatsky. 2014

821 citations recorded by the source corpus.

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.

Subfields: Atomic and Molecular Physics, and Optics, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/9c9cce12a0947011568df6dcd8a1a63ebbab4306

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In Atomic and Molecular Physics, and Optics

In Materials Chemistry

Citations in the corpus

New perspectives for Rashba spin-orbit coupling. (2015, background): “The concept of pseudospin is useful in predicting and interpreting transport properties of the various systems mentioned above, in particular when a Rashba-type pseudospinorbit coupling is present [107].”
Weyl and Dirac semimetals in three-dimensional solids (2017, background): “…2017, 2015; Jia et al., 2016; Syzranov and Radzihovsky, 2018; Šmejkal et al., 2017a; WitczakKrempa et al., 2014; Yan and Felser, 2017) and connections to related systems like nodal superconductors have been reviewed in Schnyder and Brydon, 2015; Vafek and Vishwanath, 2014; Wehling et al., 2014.”
Symmetry-protected nodal phases in non-Hermitian systems (2018, neutral): “properties, including ramifications of quantum anomalies [1, 2].”
Quantum speed limits: from Heisenberg’s uncertainty principle to optimal quantum control (2017, background): “Up to today, the Dirac equation enjoys plenty of attention [219–222], since it also found application in opto-mechanics [223], in quantum thermodynamics [224], and in condensed matter physics to describe so-called Dirac materials [225,226].”
Topological Semimetals from First Principles (2018, background): “ far from the only possible perspective one may adopt. In this regard, we note that a number of excellent longer and shorter reviews already exist in the general area of gapless topological materials (37,38,39,40,41,42,26,30,43,44,45,3,31,46,47,48,49,32). 2.DIRAC SEMIMETALS The Dirac Hamiltonian pla”
Current-induced spin-orbit torques in ferromagnetic and antiferromagnetic systems (2018, background): “Topological insulators are a class of materials displaying intriguing properties such as insulating bulk and conductive chiral and helical surfaces (Hasan and Moore, 2011; Qi and Zhang, 2011; Wehling et al., 2014).”