Abstract
Magnetic and magnetoelectric excitations in the multiferroic have been investigated at terahertz frequencies. Using different experimental geometries we can clearly separate the electroactive excitations (electromagnons) from the magnetoactive modes, i.e., antiferromagnetic resonances. Two antiferromagnetic resonances were found to coincide with electromagnons. This indicates that both excitations belong to the same mode and the electromagnons can be excited by a magnetic ac field as well. In spite of the 90° rotation of the magnetic cycloid in external magnetic fields, the electromagnons are observable for electric ac fields parallel to the axis only.
- Received 24 November 2008
DOI:https://doi.org/10.1103/PhysRevLett.102.107203
©2009 American Physical Society