In-situ electric field control of THz non-reciprocal directional dichroism in the multiferroic Ba${}_2$CoGe${}_2$O${}_7$

Abstract

Non-reciprocal directional dichroism, also called the optical-diode effect, is an appealing functional property inherent to the large class of non-centrosymmetric magnets. However, the in-situ electric control of this phenomenon is challenging as it requires a set of conditions to be fulfilled: Special symmetries of the magnetic ground state, spin-excitations with comparable magnetic- and electric-dipole activity and switchable electric polarization. We demonstrate the isothermal electric switch between domains of Ba${}_2$CoGe${}_2$O${}_7$ possessing opposite magnetoelectric susceptibilities. Combining THz spectroscopy and multiboson spin-wave analysis, we show that unbalancing the population of antiferromagnetic domains generates the non-reciprocal light absorption of spin excitations.

version accepted

References in corpus (3)

• Spin-stretching modes in anisotropic magnets: spin-wave excitations in the multiferroic Ba2CoGe2O7
• Gigantic magnetoelectric effect caused by magnetic-field-induced canted antiferromagnetic-paramagnetic transition in quasi-two-dimensional Ca${}_2$CoSi${}_2$O${}_7$ crystal
• Multiferroic properties of an åkermanite Sr${}_2$CoSi${}_2$O${}_7$ single crystal in high magnetic fields

Cited by in corpus (4)

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