Regensburg 2019 – wissenschaftliches Programm
MA 12.4: Vortrag
Montag, 1. April 2019, 18:00–18:15, H53
Thermal Hall Effect in Noncollinear Coplanar Insulating Antiferromagnets — •Alexander Mook1, Jürgen Henk1, and Ingrid Mertig1,2 — 1Institut für Physik, Martin-Luther-Universität, D-06120 Halle — 2Max-Planck-Institut für Mikrostrukturphysik, D-06120 Halle
Recently, it was predicted and demonstrated that antiferromagnets can exhibit an anomalous Hall effect , which was traditionally ascribed to ferromagnets. Here, we show that insulating antiferromagnets can exhibit a thermal Hall effect due to their collective magnetic excitations, magnons. The two necessary requirements for the existence of this Hall effect are: (i) the breaking of an effective time-reversal symmetry and (ii) a magnetic point group compatible with ferromagnetism. Since the latter does not imply the actual presence of ferromagnetism, antiferromagnets with sufficiently low symmetry may meet both requirements. Such antiferromagnets are realized, for example, on the kagome lattice in the inverse vector chiral magnetic phase, as it occurs approximately in cadmium kapellasite .
 Chen et al., PRL 112, 017205 (2014); Kübler, Felser, EPL, 108, 67001 (2014); Ajaya et al., Science Advances 2, e1501870 (2016).
 Okuma et al., PRB 95, 094427 (2017).