---

The understanding of electronic and structural phase transitions is of basic importance in condensed matter physics. In this presentation, I will concentrate on phase transitions that can be triggered externally by electronic excitations and address the how we can excite particle modes of lattice excitation, and explore how these are related to the electronic and magnetic properties and the corresponding phase transitions. The goal is to understand how and how fast we can trigger electronic transitions and how they might couple to structural motions of the atomic lattice. [1-3] These can be done using pump-probe schemes, with x-rays as a probe down to ultrafast time scales, as created by an x-ray free electron laser. The presented examples will include the charge and orbital order phase transition in half doped manganites [1,3] and multiferroic TbMnO3. I will also present very briefly newest results on the octahedral rotation transitions in simple perovskite SrTiO3 and EuTiO3, which shows opposite behaviour when triggering this phase transition. References [1] P. Beaud et al. Nature Materials 13, 923 (2014) [2] Kubacka et al. Science 343, 1333 (2014) [3] V. Esposito et al. Phys. Rev. Lett. (in press) (2017).

---

Urs Staub, Paul Scherrer Institute
Seminar Room of the Institute of Physics II
Contact: Markus Braden