We report the detection of a magnetic resonance mode in multiferroic ${\mathrm{Ba}}_{0.6}{\mathrm{Sr}}_{1.4}{\mathrm{Zn}}_2{\mathrm{Fe}}_{12}{\mathrm{O}}_{22}$ using time-domain pump-probe reflectance spectroscopy. Magnetic sublattice precession is coherently excited via picosecond thermal modification of the exchange energy. Importantly, this precession is recorded as a change in reflectance caused by the dynamic magnetoelectric effect. Thus, transient reflectance provides a sensitive probe of magnetization dynamics in materials with strong magnetoelectric coupling, such as multiferroics, revealing new possibilities for application in spintronics and ultrafast manipulation of magnetic moments.

• Received 29 September 2007

DOI:https://doi.org/10.1103/PhysRevLett.101.097603