Open AccessCharge redistribution and a shortening of the Fe—As bond at the quantum critical point of SmO 1– x F x FeAs
Author(s) -
Cheng Jie,
Dong Peng,
Xu Wei,
Liu Shengli,
Chu Wangsheng,
Chen Xianhui,
Wu Ziyu
Publication year - 2015
Publication title -
journal of synchrotron radiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.172
H-Index - 99
ISSN - 1600-5775
DOI - 10.1107/s1600577515008450
Subject(s) - redistribution (election) , superconductivity , condensed matter physics , quantum critical point , absorption edge , x ray absorption spectroscopy , k edge , doping , electronic structure , physics , absorption spectroscopy , crystallography , chemistry , materials science , quantum phase transition , phase transition , band gap , quantum mechanics , politics , political science , law
Many researchers have pointed out that there is a quantum critical point (QCP) in the F‐doped SmOFeAs system. In this paper, the electronic structure and local structure of the superconductive FeAs layer in SmO 1– x F x FeAs as a function of the F‐doping concentration have been investigated using Fe and As K ‐edge X‐ray absorption spectroscopy. Experiments performed on the X‐ray absorption near‐edge structure showed that in the vicinity of the QCP the intensity of the pre‐edge feature at the Fe‐edge decreases continuously, while there is a striking rise of the shoulder‐peak at the As edge, suggesting the occurrence of charge redistribution near the QCP. Further analysis on the As K ‐edge extended X‐ray absorption fine structure demonstrated that the charge redistribution originates mostly from a shortening of the Fe—As bond at the QCP. An evident relationship between the mysterious QCP and the fundamental Fe—As bond was established, providing new insights on the interplay between QCP, charge dynamics and the local structural Fe—As bond in Fe‐based superconductors.