08.11.2017
By combining relativistic density functional theory with an extended spin-1/2 compass-Heisenberg model, we find an antiferromagnetic single-stripe ground state with highly competing exchange interactions, involving a non-negligible interlayer coupling, which places the system at the crossover between the XY-model and Heisenberg-model regimes.
Most strikingly, we find a strong two-site “spin-compass” exchange anisotropy which is relieved by the orthorhombic distortion induced by the spin stripe order. Based on these results, we discuss the origin of the hidden-order phase and the possible formation of a spin liquid at low temperatures.
B. Kim et al., Phys. Rev. B 96, 180405(R)