Regensburg 2019 – wissenschaftliches Programm
TT 15.13: Vortrag
Montag, 1. April 2019, 18:30–18:45, H23
Enhanced Friedel oscillations by nematic fluctuations in an iron-based superconductor — •Steffen Sykora1, Zhixiang Sun1, Jose M. Guevara1, Bernd Büchner1,2,3, and Christian Hess1,3 — 1IFW Dresden, 01069 Dresden, Germany — 2Institute for Solid State Physics, TU Dresden, 01069 Dresden, Germany — 3Center for Transport and Devices, TU Dresden, 01069 Dresden, Germany
Nematic fluctuations are known to provide an additional superconducting pairing channel which is considered as a possible explanation for the large critical temperatures in iron-based superconductors. We study its influence on the impurity scattering using a minimal microscopic model of nematic fluctuations in an effective two-band system of conduction electrons. Applying a projective renormalization method to integrate out the nematic interaction we find that the impurity scattering potential can be strongly renormalized at small scattering momentum through virtual particle-hole excitations in the dxz/dyz orbital channel. For the particular material LiFeAs we explicitly calculate the Fourier-transformed local density of states and find excellent agreement with recent scanning tunneling experiments* where resonantly enhanced Friedel oscillations have been attributed to the first spectroscopic evidence of nematic fluctuations in an iron-based superconductor.