Fig. 2

Excitation spectra of Ba3CoSb2O9 along the c * direction. a Energy-momentum map of the scattering intensity along Q = (1/3, 1/3, L), for varying L, measured with E i = 3.14 meV. b, c are those along (1/2, 1/2, L) measured with E i = 3.14 and 7.74 meV, respectively. The solid lines in a are fits calculated by LSWT with J = 1.67 meV, Δ = 0.046 and \(J'\) = 0.080 meV