Regensburg 2019 – wissenschaftliches Programm
TT 15.4: Vortrag
Montag, 1. April 2019, 15:45–16:00, H23
Tracking nematic fluctuations using the Nernst effect in Co-doped LaFeAsO — •Christoph Wuttke1, Federico Caglieris1, Steffen Sykora1, Frank Steckel1, Xiaochen Hong1, Seunghyun Kim1, Rhea Kappenberger1, Saicharan Aswartham1, Sabine Wurmehl1, Sheng Ran2, Paul C. Canfield2, Bernd Büchner1,3,4, and Christian Hess1,4 — 1Leibniz-Institute for Solid State and Materials Research, IFW-Dresden, 01069 Dresden, Germany — 2Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA — 3Institut für Festkörperphysik, TU Dresden, 01069 Dresden, Germany — 4Center for Transport and Devices, Technische Universität Dresden, 01069 Dresden, Germany
We use the Nernst coefficient to track the nematic fluctuations through the Co-doped phase diagram of LaFeAsO. Similarly to our previous measurements in an 122-iron based superconductor system, we obtain a significant enhancement of the signal in the nematic fluctuation regime. The doping dependence of the Nernst coefficient exhibits a non-monotonic behavior featuring a local maximum in the vicinity of optimal doping. This peculiar doping dependence is also in agreement with our theoretical prediction and hence demonstrates the universality of the sensitivity of the Nernst effect on nematic fluctuations in iron based superconductors.