Figure 2. Magnetic diffuse neutron scattering profiles.

The incident neutron spins were polarized along the Z direction. (a) Experimentally observed profiles for the SF (left), NSF (middle) and total (right) magnetic diffuse neutron scattering cross-sections in the (h,h,l) plane above T_C at T=0.3 K. The background levels for the diffuse scattering have been subtracted by making use of the data measured with the incident neutron beam polarized along the X direction parallel to the scattering wavevector Q (see Supplementary Methods and Supplementary Fig. S3). White circles mark the Bragg spots where the background subtraction scheme is less reliable. The measurements were performed in the energy-integrated diffraction mode up to an energy of 3.64 meV. (b) Theoretically calculated magnetic profiles for SF (left), NSF (middle) and total (right) magnetic diffuse neutron scattering cross-sections in the (h,h,l) plane at T=0.3 K. The profiles were obtained as the equal-time correlators in the RPA (Supplementary Methods) to the pseudospin-1/2 model, H_D+H_se. The form factor is not included. (c,d) Neutron scattering intensity for the SF channel along [11–1] and [111] cuts, respectively, through the remnant of the pinch point (111) at T=0.3 and 1.5 K. The data were measured with a higher resolution in reciprocal space than the full (h,h,l) profiles. One or two points marking a high level of intensity at and close to the (111) point correspond to the nuclear Bragg peak. The lines are a guide to the eye. (e) Temperature dependence of the total cross-section along [11–1] cut through (1.5,1.5,1.5), as indicated in the inset.