Structural Motion far from Equilibrium: Reconstructing Interatomic Forces, Irreversible Phase Transitions, and Anharmonicity
Date | Di, 01.10.2019 | |
Time | 10:00h | |
Speaker | Dr. Samuel Teitelbaum, SLAC National Accelerator Laboratory, Stanford, US | |
Location | ETHZ, Hönggerberg Campus, HPF G-6 | |
Program | Abstract: In solids, a high energy-density optical excitation can drive materials far from equilibrium, creating new structural phases not accessible on the equilibrium phase diagram. I will discuss how the high brightness and ultrashort pulse duration of X-ray free electron lasers (XFELs) enables us to reconstruct light-modified interatomic forces, and quantify couplings between different degrees of freedom. I will also discuss a method I helped develop to image the real-time optical response of materials that do not return to equilibrium after irradiation. I will discuss how to apply these complementary approaches to a light-induced high-symmetry crystalline phase in bismuth, and a metastable structural/magnetic phase in a transition metal oxide only accessible by photoexcitation. |
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Laser & NCCR MUST Seminars |