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TT: Fachverband Tiefe Temperaturen
TT 35: Superconductivity: Fe-based Superconductors - 122 and Theory
TT 35.2: Talk
Tuesday, March 13, 2018, 09:45–10:00, A 053
Superconductivity induced changes of the phonon lifetime in Ba(Fe0.94Co0.06 )2As2 — •Maximilian Kauth1, Frank Weber1, John-Paul Castellan1, Thomas Wolf1, Thomas Keller2, and Dimitry Reznik3 — 1Institute for Solid State Physics, Karlsruhe Institute of Technology, Karlsruhe, Germany — 2Max-Planck-Institute for Sodid State Research, Stuttgart, Germany — 3Department of Physics, University of Colorado atBoulder, Boulder, Colorado, 80309, USA
We have investigated the life time of the transversal acoustic (TA) phonon mode in the Fe-based high-temperature superconductor Ba(Fe0.94Co0.06)2As2 along the [100] direction. We used the thermal neutron triple axis spectrometer (TAS) 1T at LLB at CEA Saclay and the neutron resonant spin echo (NRSE) technique at the TRISP spectrometer at the MLZ in Garching [1]. This phonon mode is the soft mode of the structural phase transition present in lower doped samples. Recent measurements showed evidence that it is sensitive to nematic fluctuations in this compound [2]. We observe a clear maximum of the TA phonon linewidth at the superconducting transition temperature TC ≈ 24 K with both measurement techniques (regular TAS and NRSE). This is the first experimental evidence of changes of the phonon lifetime in Fe-based superconductors.
MPI for Solid State Research et al., Journal of large-scale research facilities, 1, A37 (2015).
F. Weber et al., arXiv:1610.00099 (2016).