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O: Fachverband Oberflächenphysik
O 41: Poster Session III: Poster to Mini-Symposium: Ultrafast surface dynamics at the space-time limit I
O 41.2: Poster
Tuesday, March 2, 2021, 10:30–12:30, P
Exchange-striction driven ultrafast nonthermal lattice dynamics in NiO — •Yoav William Windsor1, Daniela Zahn1, Robin Kamrla2, Johannes Feldl3, Helene Seiler1, Cheng-Tien Chiang2, Manfred Rammsteiner3, Wolf Widdra2, Ralph Ernstorfer1, and Laurenz Rettig1 — 1Fritz Haber Institute def MPG, Berlin — 2Martin-Luther-Universität Halle-Wittenberg — 3Paul-Drude-Institut für Festkörperelektronik, Berlin
We use femtosecond electron diffraction to study ultrafast lattice dynamics in the highly correlated antiferromagnetic (AF) semiconductor NiO. Using the scattering vector (Q) dependence of Bragg diffraction, we introduce a Q-resolved ensemble of temperatures describing the lattice, and identify a nonthermal lattice state with preferential displacement of O compared to Ni ions, which occurs within ~0.3 ps and persists for 25 ps. We associate this with transient changes to the AF exchange striction-induced lattice distortion, supported by the observation of a transient Q-asymmetry of Friedel pairs. Our observation highlights the role of spin-lattice coupling in routes towards ultrafast control of spin order.