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DOE OSTI · 1630285

Nematic Correlation Length in Iron-Based Superconductors Probed by Inelastic X-Ray Scattering

Merritt, A. M.·Weber, F.·Casellan, J. -P.·Wolf, Th.·Ishikawa, D.·Said, A. H.·Alatas, A.·Fernandes, R. M.·Baron, A. Q. R.·Reznik, D.
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Abstract

Nematicity is ubiquitous in electronic phases of high-T c superconductors, particularly in the Fe-based systems. We used inelastic x-ray scattering to extract the temperature-dependent nematic correlation length ξ from the anomalous softening of acoustic phonon modes in FeSe, underdoped Ba(Fe 0.97 Co 0.03 ) 2 As 2 , and optimally doped Ba(Fe 0.94 Co 0.06 ) 2 As 2 . In all cases, we find that. 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 nematoelastic coupling that is likely detrimental to superconductivity.

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75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITYAcoustic phononsIron-based superconductorsNematic phase transitionStructural phase transitionSuperconducting phase transitionSuperconducting phase transitionsacoustic phononsiron-based superconductorsnematic phase transitionstructural phase transitionsuperconducting phase transition

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Merritt, A. M., Weber, F., Casellan, J. -P., Wolf, Th., Ishikawa, D., Said, A. H., Alatas, A., Fernandes, R. M., Baron, A. Q. R., Reznik, D.. 2020-04-13. Nematic Correlation Length in Iron-Based Superconductors Probed by Inelastic X-Ray Scattering. https://doi.org/10.1103/physrevlett.124.157001

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