Fig. 4: Effective model for the ferrimagnetic spin liquid.
a 2D model planar lattice without spatial distortions. b Effective lattice for the spin liquid model where Cu(3) sites as well as J1 and J6 exchange interactions have been removed. The sign of J3 is flipped to account for the absence of Cu(3) sites. c Ground-state configurations for the effective model, where each color represents a different spin direction. Ground states 1 and 2 are connected by exchanging the spins along the gray path. A second such exchange connects ground states 2 and 3. d–i Comparison of the spin structure factor of the effective model (left side of each panel) with the full two-dimensional model (right side) for three different temperatures and the two relevant sublattices (indicated in the insets of d and e).
