Terahertz magnonics using ultrathin films of samarium ferrite garnet

We have reported on terahertz magnonics, which is a signal transmission with high-energy spin waves (electromagnons) excited by THz wave. As source and medium for electromagnons, we choose Sm
3
Fe
5
O
12
ultrathin films whose magnetic properties are modified by applying an epitaxial strain. Electromagnons are successfully detected in the strained Sm
3
Fe
5
O
12
ultrathin film, using a transmittance THz time-domain spectroscopy.