Ultrafast dynamics
How fast the magnetization of a magnetic medium can be manipulated is one of the key elements in modern technology. The demand for an ever-increasing density and speed of manipulation in magnetic information storage has triggered a search for new methods for control of the magnetization by other than magnetic fields. The development of femtosecond laser sources has opened the way to create optical pulses that are much shorter than the fundamental time scales such as spin-lattice relaxation or precession times. The use of such ultrashort laser pulses allows us to excite magnetic media and to study the magnetization dynamics after ultrashort optical excitations. These new possibilities have recently led to exciting results demonstrating changes in magnetization on a (sub)picosecond timescale.
After originally focusing on the magnetization dynamics of antiferromagnets we expanded our scope by moving to the investigation of ultrafast processes in systems with strong electronic correlations in general with magnetic order as just one of its many possible manifestations. Some of the topics investigated by us are:
- Time resolved magnetoelectric switching: Reversal of magnetic order by electric fields and vice versa.
- Ultrafast magnetization dynamics beyond the three-temperature model.
- Nonthermally induced magnetization dynamics in Mott insulators and multferroics.
- Ultrafast correlation processes at surface or interface states.
- Three-dimensional control of a magnetization by polarized light pulses.
Reference
- M. Matsubara, A. Schroer, A. Schmehl, A. Melville, C. Becher, M. Trujillo-Martinez, D. G. Schlom, J. Mannhart, J. Kroha, M. Fiebig: Ultrafast optical tuning of ferromagnetism via the carrier density, Nature Communications 6, 6724 (2015)
- T. Satoh, R. Iida, T. Higuchi, M. Fiebig and T. Shimura: Writing and reading of an arbitrary optical polarization state in an antiferromagnet, Nature Photonics 9, 25 (2015)