Ultrafast manipulation of the NiO antiferromagnetic order <i>via</i> sub-gap optical excitation
Xiaocui Wang, Robin Y. Engel, Igor Vaskivskyi, Diego Turenne, Vishal Shokeen, Alexander Yaroslavtsev, Oscar Grånäs, Ronny Knut, Jan O. Schunck, Siarhei Dziarzhytski, Günter Brenner, Ru‐Pan Wang, Marion Kuhlmann, Frederik Kuschewski, Wibke Bronsch, C. Schüßler-Langeheine, Andriy Styervoyedov, S. Parkin, F. Parmigiani, Olle Eriksson, Martin Beye, H. A. Dürr
Abstract
-edge). Comparing the transient XMLD spectral line shape to ground-state measurements allows us to extract a spin temperature rise of 65 ± 5 K for time delays longer than 400 fs while at earlier times a non-equilibrium spin state is formed. We identify transient mid-gap states being formed during the first 200 fs accompanied by a band-gap reduction lasting at least up to the maximum measured time delay of 2.4 ps. Electronic structure calculations indicate that magnon excitations significantly contribute to the reduction of the NiO band gap.