TY - JOUR
T1 - Temperature-dependent transformation of the magnetic excitation spectrum on approaching superconductivity in Fe1+y-x(Ni/Cu)xTe 0.5Se0.5
AU - Xu, Zhijun
AU - Wen, Jinsheng
AU - Zhao, Yang
AU - Matsuda, Masaaki
AU - Ku, Wei
AU - Liu, Xuerong
AU - Gu, Genda
AU - Lee, D. H.
AU - Birgeneau, R. J.
AU - Tranquada, J. M.
AU - Xu, Guangyong
PY - 2012/11/28
Y1 - 2012/11/28
N2 - Spin excitations are one of the top candidates for mediating electron pairing in unconventional superconductors. Their coupling to superconductivity is evident in a large number of systems, by the observation of an abrupt redistribution of magnetic spectral weight at the superconducting transition temperature, Tc, for energies comparable to the superconducting gap. Here we report inelastic neutron scattering measurements on Fe-based superconductors, Fe1-x(Ni/Cu)xTe0.5Se 0.5, that emphasize an additional signature. The overall shape of the low energy magnetic dispersion changes from two incommensurate vertical columns at TTc to a distinctly different U-shaped dispersion at low temperature. Importantly, this spectral reconstruction is apparent for temperatures up to ∼3Tc. If the magnetic excitations are involved in the pairing mechanism, their surprising modification on the approach to Tc demonstrates that strong interactions are involved.
AB - Spin excitations are one of the top candidates for mediating electron pairing in unconventional superconductors. Their coupling to superconductivity is evident in a large number of systems, by the observation of an abrupt redistribution of magnetic spectral weight at the superconducting transition temperature, Tc, for energies comparable to the superconducting gap. Here we report inelastic neutron scattering measurements on Fe-based superconductors, Fe1-x(Ni/Cu)xTe0.5Se 0.5, that emphasize an additional signature. The overall shape of the low energy magnetic dispersion changes from two incommensurate vertical columns at TTc to a distinctly different U-shaped dispersion at low temperature. Importantly, this spectral reconstruction is apparent for temperatures up to ∼3Tc. If the magnetic excitations are involved in the pairing mechanism, their surprising modification on the approach to Tc demonstrates that strong interactions are involved.
UR - http://www.scopus.com/inward/record.url?scp=84870433641&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.109.227002
DO - 10.1103/PhysRevLett.109.227002
M3 - Article
AN - SCOPUS:84870433641
SN - 0031-9007
VL - 109
JO - Physical Review Letters
JF - Physical Review Letters
IS - 22
M1 - 227002
ER -