Dynamics of electromagnons in GdMn2 O5: Role of Gd-Mn exchange interaction

Multiferroic materials, characterized by the existence of coupled magnetic and electric orders, offer a rich platform for studying magnetoelectric excitations such as electromagnons. In this study, we have investigated the electromagnon excitations in GdMn2O5, a rare-earth manganite known for its strong magnetoelectric effects. Using terahertz time-domain spectroscopy performed under an external magnetic field up to 7 T, we identified an electromagnon at 36cm-1 (4.5 meV) that emerges below the commensurate magnetic ordering temperature (TN2≈33K). Our results show that the electromagnon in GdMn2O5 is highly sensitive to the spin configurations of Gd and Mn, which are strongly influenced by the Gd-Mn exchange interaction. The observed hysteresis in the electromagnon spectrum, corresponding to the magnetic hysteresis, further indicates a strong coupling between magnetic and electric orders in this material.