Veranstaltung

| 21-09-2020

IKZ Kolloquium / Onlineseminar - 21.09.2020

Dr. Mathias Sander - "Ultrafast strain engineering of SrTiO₃"

Veranstaltungsort:
Aus aktuellem Anlass findet das Seminar online statt.
Über den genauen Ablauf, inklusive Bekanntmachung der Meeting-ID, werden wir kurzfristig informieren.


Dozent:
Dr. Mathias Sander
Paul-Scherrer Institut, Villingen, Schweiz


Abstract:
The manipulation of material properties via substrate induced epitaxial lattice strain, so called strain engineering, has proven to be a powerful technique to generate new phases, elevate the critical temperature of superconductivity [1] or induce room temperature ferroelectricity in thin crystalline SrTiO3 layers [2]. During my talk I will present a new concept to manipulate properties of a thin SrTiO3 film on ultrafast time scales by uniaxial coherent strain generated by ultrashort optical laser pulses [3]. The ultrafast coupling of GHz acoustic strain to internal degrees of freedom of the SrTiO3 unit cell is monitored in time by femtosecond x-ray diffraction at the Bernina end station of the Swiss Free Electron Laser. A comparison of experimental results and Density Functional Theory (DFT) reveals a coupling of octahedral rotations and GHz acoustic strain and suggests a strain induced polar displacement in SrTiO3, paving the way for ultrafast strain engineering.


[1] Stemmer et al, Science Advances, Vol. 5, no. 4 2019
[2] Xu et al, Nature Communications, Vol. 11, no. 3141 2020
[3] Sander et al, J. Synchrotron Rad., 26, 1253-1259, 2019

 

Das Kolloquium findet in englischer Sprache statt.