Regensburg 2019 – scientific programme

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MA: Fachverband Magnetismus

MA 25: Topological Semimetals - Theory (joint session TT/MA)

MA 25.11: Talk

Wednesday, April 3, 2019, 12:15–12:30, H22

Anomaly transport normally explained — •Klaus Morawetz — Münster University of Applied Sciences, Stegerwaldstrasse 39, 48565 Steinfurt, Germany — International Institute of Physics - UFRN, Campus Universitário Lagoa nova, 59078-970 Natal, Brazil

The anomalous term ∼E^→B^→ in the balance of the chiral density can be rewritten as quantum current in the classical balance of density. Therefore it does not violate classical conservation laws as it is claimed to be caused by quantum fluctuations. Moreover this term is derived from the quantum kinetic equations for systems with SU(2) structure within a completely conserving approach. Therefore the origin of this term is not a unique signal of symmetry-breaking terms in the field-theoretical Lagrangian. Regularization-free density and pseudospin currents are calculated in Graphene and Weyl-systems realized as the infinite-mass limit of electrons with quadratic dispersion and a proper spin-orbit coupling. The intraband and interband conductivities are discussed. The optical conductivity agrees well with the experimental values using screened impurity scattering and an effective Zeeman field. The universal value of Hall conductivity is shown to be modified due to the Zeeman field.
arXiv:1809.01547, arXiv:1806.06214, Phys. Rev. B 94 (2016) 165415, Phys. Rev. B 92 (2015) 245425, errata: Phys. Rev. B93 (2016) 239904(E), Phys. Rev. B 92 (2015) 245426