In:
Nature Communications, Springer Science and Business Media LLC, Vol. 7, No. 1 ( 2016-12-19)
Abstract:
Iron-based superconductivity develops near an antiferromagnetic order and out of a bad-metal normal state, which has been interpreted as originating from a proximate Mott transition. Whether an actual Mott insulator can be realized in the phase diagram of the iron pnictides remains an open question. Here we use transport, transmission electron microscopy, X-ray absorption spectroscopy, resonant inelastic X-ray scattering and neutron scattering to demonstrate that NaFe 1− x Cu x As near x ≈0.5 exhibits real space Fe and Cu ordering, and are antiferromagnetic insulators with the insulating behaviour persisting above the Néel temperature, indicative of a Mott insulator. On decreasing x from 0.5, the antiferromagnetic-ordered moment continuously decreases, yielding to superconductivity ∼ x =0.05. Our discovery of a Mott-insulating state in NaFe 1− x Cu x As thus makes it the only known Fe-based material, in which superconductivity can be smoothly connected to the Mott-insulating state, highlighting the important role of electron correlations in the high- T c superconductivity.
Type of Medium:
Online Resource
ISSN:
2041-1723
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2016
detail.hit.zdb_id:
2553671-0
Bookmarklink