# Linearly polarized GHz magnetization dynamics of spin helix modes in the ferrimagnetic insulator Cu$_{2}$OSeO$_{3}$

Stasinopoulos, I.; Weichselbaumer, S.; Bauer, A.; Waizner, J.; Berger, H.; Garst, Markus ; Pfleiderer, C.; Grundler, D.

##### Abstract:
Linear dichroism — the polarization dependent absorption of electromagnetic waves— is routinely exploited in applications as diverse as structure determination of DNA or polarization filters in optical technologies. Here filamentary absorbers with a large length-to-width ratio are a prerequisite. For magnetization dynamics in the few GHz frequency regime strictly linear dichroism was not observed for more than eight decades. Here, we show that the bulk chiral magnet Cu$_{2}$OSeO$_{3}$ exhibits linearly polarized magnetization dynamics at an unexpectedly small frequency of about 2 GHz at zero magnetic field. Unlike optical filters that are assembled from filamentary absorbers, the magnet is shown to provide linear polarization as a bulk material for an extremely wide range of length-to-width ratios. In addition, the polarization plane of a given mode can be switched by 90° via a small variation in width. Our findings shed a new light on magnetization dynamics in that ferrimagnetic ordering combined with antisymmetric exchange interaction offers strictly linear polarization and cross-polarized modes for a broad spectrum of sample shapes at zero field. ... mehr

 Zugehörige Institution(en) am KIT Institut für Theoretische Festkörperphysik (TFP) Publikationstyp Zeitschriftenaufsatz Publikationsmonat/-jahr 12.2017 Sprache Englisch Identifikator ISSN: 2045-2322 KITopen-ID: 1000128909 Erschienen in Scientific reports Verlag Nature Research Band 7 Heft 1 Seiten Art.-Nr.: 7037 Vorab online veröffentlicht am 01.08.2017 Nachgewiesen in ScopusWeb of ScienceDimensions
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