Magnonlike dispersion of spin resonance in Ni-doped BaFe2As2

Phys Rev Lett. 2013 Apr 26;110(17):177002. doi: 10.1103/PhysRevLett.110.177002. Epub 2013 Apr 24.

Abstract

Inelastic neutron scattering measurements on Ba(Fe0.963Ni0.037)2As2 manifest a neutron spin resonance in the superconducting state with anisotropic dispersion within the Fe layer. Whereas the resonance is sharply peaked at the antiferromagnetic (AFM) wave vector Q(AFM) along the orthorhombic a axis, the resonance disperses upwards away from Q(AFM) along the b axis. In contrast to the downward dispersing resonance and hourglass shape of the spin excitations in superconducting cuprates, the resonance in electron-doped BaFe2As2 compounds possesses a magnonlike upwards dispersion.