Signatures of Bond-Dependent Magnetism

J A M Paddison, Scattering Signatures of Bond-Dependent Magnetic Interactions, Phys Rev Lett 125, 247202 (2020)

Changing the signs of bond-dependent magnetic interactions JA and JB (defined in the paper) has qualitative and quantitative signatures in magnetic diffuse scattering patterns; the calculations here show scattering patterns in the (hhl) plane for the honeycomb lattice.

Bond-dependent magnetic interactions can generate exotic phases such as Kitaev spin-liquid states. Experimentally determining the values of bond-dependent interactions is a challenging but crucial problem. Here, I show that each symmetry-allowed nearest-neighbor interaction on triangular and honeycomb lattices has a distinct signature in paramagnetic neutron-diffraction data, and that such data contain sufficient information to determine the spin Hamiltonian unambiguously viaunconstrained fits. Moreover, I show that bond-dependent interactions can often be extracted from powder-averaged data. These results facilitate experimental determination of spin Hamiltonians for materials that do not show conventional magnetic ordering.