|標題：||第51回極限コヒーレント光科学セミナー：Ultrafast manipulation of magnetic structures probed by x-rays|
|講師：||Dr. Urs Staub|
|所属：||Swiss Light Source, Paul Scherrer Institut|
|要旨：||Being able to manipulate magnetic structures in non-trivial ways such as by the application of a magnetic field, is interesting from fundamental point of view as well as from that of applications. Manipulating them on ultrafast time scales is even more exciting and challenging. Here I like to address the ultrafast magnetization dynamics of antiferromagnets, for which a microscopic understanding of the spin dynamics can be obtained by x-ray (resonant) diffraction using ultra-short x-ray pulses, today obtainable on X-ray-Free-Electron-Laser (XFEL) sources, such as the LCLS and SACLA. I will give examples on ultra-fast demagnetization on simple elemental Ho , on CuO, [2,3] which are in strong contrast to the results obtained on TbMnO3.  At the end I hope I will show you the potential to obtain ultrafast all optical switching in oxides by switching the magnetic structure and the ferroelectric polarization in a multiferroic. 
 L. Rettig et al., submitted
 S. L. Johnson et al., Phys. Rev. Lett. 108, 037203 (2012).
 U. Staub et al., Phys. Rev. B 89, 220401(R) (2014).
 J. Johnson et al., Phys. Rev. B in press (arXiv:1507.06628)
 T. Kubaka et al., Science 343,1333 (2014).
|世話人：||和達 大樹 (内線：63400)
e-mail: wadati :at: issp.u-tokyo.ac.jp