Pronounced spin precessions are observed in a geometry with negligible canting of the magnetization in ferromagnetic La0.67Ca 0.33MnO3 thin films using the time-resolved magneto-optical Kerr effect. The precession amplitude monotonically decreases with increasing field, indicating that the coherent spin rotation may be triggered by a transient exchange field and not by demagnetization and/or anisotropy field modulation. We attribute the transient exchange field to emergent antiferromagnetic interactions due to charge transfer and modification of the kinetic energy of eg electrons under optical excitation.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)