"Ultrafast dynamics of localized magnetic moments in the unconventional Mott insulator Sr2 IrO4"

O Krupin: G L Dakovski, B J Kim, J W Kim, Jungho Kim, S Mishra, Yi-De Chuang, C R Serrao, W-S Lee, W F Schlotter, M P Minitti, D Zhu, D Fritz, M Chollet, R Ramesh, S L Molodtsov and J J Turner; Journal of Physics: Condensed Matter, 06/16/16.

Additional Authors: G L Dakovski, B J Kim, J W Kim, Jungho Kim, S Mishra, Yi-De Chuang, C R Serrao, W-S Lee, W F Schlotter, M P Minitti, D Zhu, D Fritz, M Chollet, R Ramesh, S L Molodtsov and J J Turner

Abstract:

We report a time-resolved study of the ultrafast dynamics of the magnetic moments formed by the Jeff = 1/2 states in Sr2IrO4 by directly probing the localized iridium 5d magnetic state through resonant x-ray diffraction. Using optical pump–hard x-ray probe measurements, two relaxation time scales were determined: a fast fluence-independent relaxation is found to take place on a time scale of 1.5 ps, followed by a slower relaxation on a time scale of 500 ps–1.5 ns.