Berlin 2018 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 3: Ultrafast Electron and spin dynamics at interfaces I

O 3.9: Vortrag

Montag, 12. März 2018, 12:30–12:45, MA 005

Ultrafast electron and spin dynamics in antiferromagnetic rare-earth intermetallics — •Y. W. Windsor¹, C. Nicholson¹, A. Fedorov², M. Puppin¹, K. Kummer³, K. Kliemt⁴, C. Krellner⁴, C. Schüßler-Langeheine⁵, N. Pontius⁵, U. Staub⁶, M. Wolf¹, R. Ernstorfer¹, D. V. Vyalikh⁷, and L. Rettig¹ — ¹Fritz-Haber-Institut (DE) — ²IFW Dresden (DE) — ³ESRF (FR) — ⁴Goethe-Univ. (DE) — ⁵HZB (DE) — ⁶PSI (CH) — ⁷DIPC (ES)

Antiferromagnets (AFM) promise much faster magnetization dynamics than ferromagnets (FM), and so are promising candidates for future ultrafast spintronic applications. Here we study the ultrafast electron and spin dynamics in RE-Rh2Si2 AFMs (RE is a rare earth), which exhibit an intriguing coupling of bulk AFM order to a FM surface evidenced by a spin-split surface state [1].

Using XUV time-resolved ARPES (trARPES) and time-resolved resonant X-ray diffraction (trRXD), we obtain a comprehensive view of the ultrafast demagnetization of the bulk AFM and the FM surface (following optical excitation). We observe similar dynamics for the two orders (bulk AFM order and FM spin split surface state), indicating a strong coupling between the two. Comparison of the demagnetization timescales for different RE ions suggests a strong influence of the 4f L moment and spin-lattice coupling on demagnetization, similar to studies on RE metals [2]. Finally, we observe a coherent rotation of the entire AFM structure, which can be controlled by laser fluence.

[1] Güttler, Sci.Rep. 6, 24254 (2016)

[2] Wietstruck, PRL 106, 127401 (2011)