Regensburg 2019 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 5: Superconductivity: Fe-based Superconductors - FeSe and 122
TT 5.1: Vortrag
Montag, 1. April 2019, 09:30–09:45, H23
Elastoresistance and resistivity anisotropy in FeSe under uniaxial strain — •Alexander Steppke1, Jack Bartlett1,2, Suguru Hosoi3, Takasada Shibauchi3, Andrew Mackenzie1,2, and Clifford Hicks1 — 1Max-Planck Institute for Chemical Physics of Solids, Nöthnitzerstr. 40, Dresden, 01187, Germany — 2University of St Andrews, School of Physics and Astronomy, St Andrews KY16 9SS, United Kingdom — 3University of Tokyo, Department of Advanced Materials Science, Kashiwa, Chiba 277-8561, Japan
The phase diagram of iron-based superconductors features breaking of rotational symmetry, the electronic nematic order. Its microscopic origin and consequences for the transport and magnetic properties are under intense debate. We set out to tune the crystal structure of FeSe using uniaxial strain. Without magnetic order at ambient pressure this material undergoes a tetragonal-to-orthorombic transition around 90 K. Whereas this transition only leads to small changes in the lattice constants, the electrical transport, i.e., the resistivity can exhibit anisotropies of several percent. With the development of a sample-on-platform technique we were able to apply uniaxial strains up to 0.6% in a wide temperature range for this very ductile material. This enables continuous tuning of FeSe from the twinned to fully detwinned state and beyond. We report on the non-monotonic elastoresistance, the resistance anisotropy and characterize the contribution of domains to the resistivity within the nematic phase.