Berlin 2018 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 20: Topological Semimetals II

TT 20.9: Talk

Monday, March 12, 2018, 17:15–17:30, A 053

Quantum anomalies in strained Weyl semimetals — Sthitadhi Roy¹, •Jan Behrends¹, Michael Kolodrubetz², Jens H. Bardarson³, Nathan Goldman⁴, Adolfo G. Grushin^2,5, and Roni Ilan⁶ — ¹Max-Planck-Institut für Physik komplexer Systeme, 01187 Dresden, Germany — ²Department of Physics, University of California, Berkeley, California 94720, USA — ³Department of Physics, KTH Royal Institute of Technology, Stockholm, SE-106 91 Sweden — ⁴Center for Nonlinear Phenomena and Complex Systems, Université Libre de Bruxelles, CP 231, Campus Plaine, B-1050 Brussels, Belgium — ⁵Institut Néel, CNRS and Université Grenoble Alpes, F-38042 Grenoble, France — ⁶Raymond and Beverly Sackler School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978, Israel

The chiral anomaly gives the topological response of Weyl semimetals to an external perturbation, insensitive to local details of the Hamiltonian. The recent identification of strain as axial fields in these materials gives rise to other anomalies, known from high-energy theory. However, these anomalies driven by axial fields are not necessary gauge-invariant or charge-conserving; in fact, two different formulations exist, realizing just one of these conditions. In this work, we propose a way to resolve this ambiguity, supported by a lattice model that provides an intuitive picture. We identify experimental signatures and argue about their stability in presence of disorder.