Fig. 3.

Evolution of the angle dependence of τ/H with increasing magnetic field at low temperatures. a At 4 K, τ/H evolves from a characteristic sin 2θ angle dependence at small fields to b a correlation-driven sin θ sign(cos θ) angle dependence at high fields. The discontinuity in τ/H across the c-axis (θ = 90°) implies Ising-like behavior of the magnetization along the crystallographic b-direction. c The angle dependence of τ/H in the bc-plane at discrete field values shows a clear deviation from sin 2θ behavior that persists up to 55 T