Document Type
Article
Publication Date
8-14-2019
Publication Title
Physical Review B
Publisher
American Physical Society
Volume
100
Issue
6
First page number:
1
Last page number:
6
Abstract
The FeSe-based superconductors exhibit a wide range of critical temperature Tcunder a variety of material and physical conditions, but extensive studies to date have yet to produce a consensus view on the underlying mechanism. Here we report on a systematic Raman-scattering work on intercalated FeSe superconductors Lix(NH3)yFe2Se2 and (Li,Fe)OHFeSe compared to pristine FeSe. All three crystals show an anomalous power-law temperature dependence of phonon linewidths, deviating from the standard anharmonic behavior. This intriguing phenomenon is attributed to electron-phonon coupling effects enhanced by electron correlation, as evidenced by the evolution of the A1g Raman mode. Meanwhile, an analysis of the B1g mode, which probes the out-of-plane vibration of Fe, reveals a lack of influence by previously suggested structural parameters, and instead indicates a crucial role of the joint density of states in determining Tc. These findings identify carrier doping as the direct factor driving and modulating superconductivity in FeSe-based compounds.
Disciplines
Physics
File Format
File Size
770 KB
Language
English
Repository Citation
Zhang, A.,
Ma, X.,
Wang, Y.,
Sun, S.,
Lei, B.,
Lei, H.,
Chen, X.,
Wang, X.,
Chen, C.,
Zhang, Q.
(2019).
Probing the Direct Factor for Superconductivity in FeSe-Based Superconductors by Raman Scattering.
Physical Review B, 100(6),
1-6.
American Physical Society.
http://dx.doi.org/10.1103/PhysRevB.100.060504