Abstract
Ultrafast lattice and spin dynamics in an antiferromagnet NiO were studied via reflection and transmission experiments using polarization spectroscopy along with the pump-probe technique. The damped oscillations observed in the reflection experiment are not of spin origin but can be attributed to an interference effect caused by the probe pulse reflected by a propagating wave packet of acoustic phonons. Terahertz oscillations of coherent magnons were observed in the transmission experiment. Three antiferromagnetic modes were observed at low temperatures. As the temperature increases, the two higher modes degenerate above 250 K and then soften toward the Nel temperature (523 K).
- Received 25 April 2012
DOI:https://doi.org/10.1103/PhysRevB.86.094301
©2012 American Physical Society