학술논문
Two-magnon Raman scattering in A$_{0.8}$Fe$_{1.6}$Se$_2$ systems: competition between superconductivity and antiferromagnetic order
Document Type
Working Paper
Author
Source
Phys. Rev. B 85, 214508 (2012)
Subject
Language
Abstract
We have performed Raman-scattering measurements on high-quality single crystals of A$_{0.8}$Fe$_{1.6}$Se$_2$ superconductors of several compositions. We find a broad, asymmetric peak around 1600 cm$^{-1}$ (200 meV), which we identify as a two-magnon process involving optical magnons. The intensity of the two-magnon peak falls sharply on entering the superconducting phase. This effect, which is entirely absent in the non-superconducting system KFe$_{1.5}$Se$_2$, requires a strong mutual exclusion between antiferromagnetism and superconductivity arising from proximity effects within regions of microscale phase separation.
Comment: 8 pages, 5 figures
Comment: 8 pages, 5 figures