Fig. 5: Coupling of magnetic order and charge density wave in DyTe₃, tracked by small-angle neutron scattering (SANS) in a magnetic field along the c-axis at T = 2 K.

a Experimental geometry of the SANS experiment. Orange plate, blue rectangle, k_in, k_out, and Q are the sample, the area detector – shifted from the center axis to catch reflections with larger \(\left\vert {{{{{{{\bf{Q}}}}}}}}\right\vert\) – incoming/outgoing neutron beam wavevector, and the momentum transfer of elastic scattering, respectively. A wedge of three-dimensional Q space is covered by rotating the sample in steps (angle ω, see “Methods”). b–e Scattering intensity in (0KL) cuts of momentum space (upper) and linecuts along (00L) (lower), for intensity integrated along the K-direction within the orange and red dashed boxes. The magnetic field induces a transition to ferroic stacking, K = 0. f Integrated intensity of various reflections as a function of magnetic field, covering three magnetic phases. Error bars correspond to statistical uncertainties of Gaussian fits to the extracted linecuts, c.f. c, e. Inset of e: experimental ratio γ = I(0, −2, −0.293)/I(0, 0, −0.293) in Phase V, compared to simulations for fan-like orders (spin plane indicated, green and gray dashed lines) and a helimagnetic (longitudinal-cone, red dashed line) order. The experiments are consistent with a slightly distorted, conical state of the same period as the underlying charge order. Error bars are derived by error propagation from the statistical uncertainties in (f).