Speaker
Frank Weber
(Karlsruhe Institute of Technology)
Description
Nematicity is ubiquitous in electronic phases of high-$T_c$ superconductors, particularly in the Fe-based systems. We used inelastic neutron and x-ray scattering to extract the temperature-dependent nematic correlation length $\xi$ from the anomalous softening of acoustic phonon modes in Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$ and FeSe. In all cases, we find that $\xi$ is well described by a power law $(T – T_{0})^{-1/2} $ extending over a wide temperature range. Combined with the previously reported Curie-Weiss behavior of the nematic susceptibility, these results point to the mean-field character of the nematic transition, which we attribute to a sizable nemato-elastic coupling that is likely detrimental to superconductivity.
Primary authors
Dr
Adrian Merritt
(Forschungszentrum Jülich)
Prof.
Raphael Fernandes
(University of Minnesota)
Frank Weber
(Karlsruhe Institute of Technology)
Prof.
Dmitry Reznik
(University of Colorado)
Co-authors
Dr
Ahmet Alatas
(Argonne National Laboratory)
Dr
Alfred Baron
(RIKEN SPring-8 Center)
Dr
Ayman Said
(Argonne National Laboratory)
Dr
John-Paul Castellan
(CEA Saclay)
