Strong interplay between stripe spin fluctuations, nematicity and superconductivity in FeSe.
Nat Mater
; 15(2): 159-63, 2016 Feb.
Article
em En
| MEDLINE
| ID: mdl-26641018
ABSTRACT
In iron-based superconductors the interactions driving the nematic order (that breaks four-fold rotational symmetry in the iron plane) may also mediate the Cooper pairing. The experimental determination of these interactions, which are believed to depend on the orbital or the spin degrees of freedom, is challenging because nematic order occurs at, or slightly above, the ordering temperature of a stripe magnetic phase. Here, we study FeSe (ref. )-which exhibits a nematic (orthorhombic) phase transition at Ts = 90 K without antiferromagnetic ordering-by neutron scattering, finding substantial stripe spin fluctuations coupled with the nematicity that are enhanced abruptly on cooling through Ts. A sharp spin resonance develops in the superconducting state, whose energy (â¼4 meV) is consistent with an electron-boson coupling mode revealed by scanning tunnelling spectroscopy. The magnetic spectral weight in FeSe is found to be comparable to that of the iron arsenides. Our results support recent theoretical proposals that both nematicity and superconductivity are driven by spin fluctuations.
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1
Base de dados:
MEDLINE
Idioma:
En
Revista:
Nat Mater
Assunto da revista:
CIENCIA
/
QUIMICA
Ano de publicação:
2016
Tipo de documento:
Article
País de afiliação:
China