1304.6657 (M. G. Kim et al.)

Magnonlike dispersion of spin resonance in Ni-doped BaFe$_2$As$_2$    [PDF]

M. G. Kim, G. S. Tucker, D. K. Pratt, S. Ran, A. Thaler, A. D. Christianson, K. Marty, A. Podlesnyak, S. L. Bud'ko, P. C. Canfield, A. Kreyssig, A. I. Goldman, R. J. McQueeney

Inelastic neutron scattering measurements on Ba(Fe$_{0.963}$Ni$_{0.037}$)$_2$As$_2$ manifest a neutron spin resonance in the superconducting state with anisotropic dispersion within the Fe layer. Whereas the resonance is sharply peaked at 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 hour-glass shape of the spin excitations in superconducting cuprates, the resonance in electron-doped BaFe$_2$As$_2$ compounds possesses a magnon-like upwards dispersion.

View original: http://arxiv.org/abs/1304.6657