Hidden multipolar orders of dipole-octupole doublets on a triangular lattice

Understand

Motivated by the recent development in strong spin-orbit-coupled materials, we consider the dipole-octupole doublets on the triangular lattice.

• We propose the most general interaction between these unusual local moments.
• Due to the spin-orbit entanglement and the special form of its wavefunction, the dipole-octupole doublet has a rather peculiar property under the lattice symmetry operation.
• As a result, the interaction is highly anisotropic in the pseudospin space, but remarkably, is uniform spatially.