2008/11/25 by Noriaki Kida, N. Kida, Yuichi Yamasaki +7
Materials Science · Physics and Astronomy · #Antiferromagnetism #Excitation #Ferroelectricity #Magnetic and transport properties of perovskites and related materials #Magnetic properties of thin films #Multiferroics and related materials #Polarization (electrochemistry) #Spin (aerodynamics) #Spin polarization #Terahertz radiation #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1143/jpsj.77.123704
published as J. Phys. Soc. Jpn. 77, 123704 (2008) · 11 pages including 3 figures
arxiv created 2008/11/25 · openalex publication_date 2008/11/25 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A broad continuum-like spin excitation (1--10 meV) with a peak structure around 2.4 meV has been observed in the ferroelectric ab spiral spin phase of Gd0.7Tb0.3MnO3 by using terahertz (THz) time-domain spectroscopy. Based on a complete set of light-polarization measurements, we identify the spin excitation active for the light E vector only along the a-axis, which grows in intensity with lowering temperature even from above the magnetic ordering temperature but disappears upon the transition to the A-type antiferromagnetic phase. Such an electric-dipole active spin excitation as observed at THz frequencies can be ascribed to the two-magnon excitation in terms of the unique polarization selection rule in a variety of the magnetically ordered phases.