Berlin 2018 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

MA: Fachverband Magnetismus

MA 18: Multiferroics and magnetoelectrics I (joint session MA/KFM)

MA 18.10: Vortrag

Dienstag, 13. März 2018, 12:00–12:15, EB 202

Directional dichroism via para-magnetoelectric effect in Sr₂CoSi₂O₇ — •Dániel G. Farkas¹, Dávid Szaller¹, Vilmos Kocsis^1,2, Sándor Bordács¹, István Kézsmárki¹, Bence Bernáth³, Dmytro Kamenskyi³, Laur Peedu⁴, Johan Viirok⁴, Toomas Rõõm⁴, Urmas Nagel⁴, Péter Balla⁵, and Karlo Penc⁵ — ¹BUTE, Hungary — ²RIKEN CEMS, Japan — ³HFML, Netherlands — ⁴KBFI, Estonia — ⁵WRCP, Hungary

Magnetoelectric multiferroics have been attracting enormous interest due to their potential in information technology applications. An exotic phenomenon, directional dichroism (DD) has been reported for spin excitations in multiferroic melilite single crystals and proposed as a new principle of directional light switches operating in the THz region [1].

Applications of multiferroic compounds seem to be limited to low temperatures where electric and magnetic order coexist. However, recent studies on melilites [2] revealed that an external magnetic field can recover the electric polarization via the para-magnetoelectric effect even above T_N = 7 K. Based on these static results we can also expect DD to emerge in the paramagnetic phase of melilites.

Indeed we have found strong DD in the paramagnetic phase of Sr₂CoSi₂O₇ in high magnetic field. A simple single-ion model was developed, which described the main features of the high temperature directional dichroism.

[1] I. Kézsmárki, D. Szaller et al. Nat. Commun. 5, 3203 (2013).

[2] M. Akaki et al., Phys. Rev. B 86, 060413(R) (2012).