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Fabrication and Characterization of Superconducting Resonators
Published on: May 21, 2016
Is LaFeAsO1-xFx an electron-phonon superconductor?
L Boeri1, O V Dolgov, A A Golubov
1Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany.
Physical Review Letters
|September 4, 2008
Summary
Electron-phonon coupling in LaFeAsO1-xFx superconductors is too weak to explain their high critical temperatures (Tc). Strong-correlation effects likely play a crucial role in these iron-based materials.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Superconductivity
Background:
- The newly discovered superconductor LaFeAsO1-xFx presents a new class of iron-based superconductors.
- Understanding the mechanism behind their superconductivity is crucial for materials science and condensed matter physics.
Purpose of the Study:
- To calculate the electron-phonon coupling in LaFeAsO1-xFx.
- To determine if electron-phonon coupling is sufficient to explain the observed critical temperatures (Tc).
Main Methods:
- Linear response theory was employed to calculate electron-phonon coupling.
- The Migdal-Eliashberg theory was used to estimate the maximum Tc based on calculated parameters.
Main Results:
- For pure LaFeAsO, the calculated electron-phonon coupling constant (lambda) and logarithmic-averaged frequency (omegaln) yield a maximum Tc of 0.8 K.
- For F-doped compounds, predicted coupling constants are even smaller.
- A 5-6 times larger coupling constant is required to match experimental Tc values.
Conclusions:
- Electron-phonon coupling alone is insufficient to explain superconductivity in the Fe-As-based superconductor family.
- Strong-correlation effects are likely significant contributors to superconductivity in these materials.
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