Dresden 2014 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 40: Multiferroics I (organized by MA)

TT 40.5: Vortrag

Dienstag, 1. April 2014, 10:30–10:45, BEY 118

Magnetoelectric monopoles in bulk periodic solids — •Michael Fechner¹, Eric Bousquet¹, Alexander Balatsky², Nicoal A. Spaldin¹, and Lars Nordström³ — ¹ETH Zürich, Department for Materials Theory, Zürich, Switzerland — ²NORDITA, KTH Royal Institute of Technology and Stockholm University, Stockholm, Sweden — ³Department of Physics and Astronomy, Uppsala University, Sweden

The magnetoelectric (ME) response is described by a second rank tensor that can be decomposed into irreducible isotropic diagonal, antisymmetric and trace-free part. Here we show that the former component can be identified with a ferroic ordering of magnetoelectric monopoles[1]. We further develop a scheme to calculate the ME monopole in bulk periodic solids, by exploiting similarities to the ferroelectric polarization. Finally, as an example we present results for the series of lithium transition metal phosphate compounds (LiMPO₄, with M = Co, Fe and Ni), which include both ferromonopolar and antiferromonopolar ordered cases. We predict for the latter case a q-dependent diagonal ME effect.

[1] N . A. Spaldin et al., PRB 88, 094429 (2013)