Spin excitations as in hole-doped Ba$_{0.67}$K$_{0.33}$Fe$_{2}$As$_{2}$ superconductor

We used inelastic neutron scattering to study the optimally doped Ba$_{0.67}$K$_{0.33}$Fe$_{2}$As$_{2}$ (Tc=38K). In contrast to electron doped counterpart, we found that resonance is almost none-L dependence as shown in Fig.1 (b), but the spin gaps are. It is gaped along (0.5,0.5,0), however essentially gapless along (0.5,0.5,1). Meanwhile, the spin correlation is strongly temperature dependence which has not been observed in electron-doped 122 materials at all. The above findings clearly suggest that hole-doped region is indeed different from electron-doped region.