[Zurück]

D. Szaller, T. Kain, V. Dziom, L. Weymann, A. M. Shuvaev, Anna Pimenov, A. Pimenov et al.:
"One-way transparency at the spin-wave resonances of multiferroics";
Hauptvortrag: From Solid State to BioPhysics IX: From Basic to Life Sciences, Dubrovnik, Kroatien (eingeladen); 16.06.2018 - 23.06.2018.

In physical systems violating two fundamental symmetries, time reversal and spatial inversion, the strength of absorption for two counter-propagating light beams can be different irrespective of the polarization state of light [1]. Until recent experiments on magnetoelectric multiferroic crystals [2, 3], where the simultaneous ferroelectric and magnetic order breaks the spatial-inversion and time-reversal symmetry, respectively, this non-reciprocal effect was generally found to be weak.
Non-reciprocal absorption in the far-infrared spectral range is the consequence of the optical magnetoelectric effect, i.e. the strongly coupled dynamics of spins and local electric dipoles in multiferroics. Materials with strong static magneto-electric effect are the most promising candidates for the realization of one-way transparency [4]. Our recent studies on several of these compounds, including Ba2CoGe2O7 [3, 5], SmFe3(BO3)4 [6], Ni3TeO6 and BiFeO3, show that magnetoelectric spin excitations efficiently generate directional optical anisotropy leading to one-way transparency [5]. Unidirectional optical properties, widely present among multiferroics, can open a new horizon in photonics [5, 7].

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[2] M. Saito et al., Phys. Rev. Lett. 101, 117402 (2008).
[3] S. Bordács et al., Nat. Phys. 8, 734 (2012).
[4] D. Szaller et al, Phys. Rev. B 89, 184419 (2014).
[5] I. Kézsmárki et al., Nat. Commun. 5, 3203 (2014).
[6] A. M. Kuz´menko et al, Phys. Rev. Lett. 120, 027203 (2018).
[7] D. Szaller et al., Phys. Rev. B 87, 014421 (2013).