A quantum liquid of magnetic octupoles on the pyrochlore lattice

Understand

Spin liquids are highly correlated yet disordered states formed by the entanglement of magnetic dipoles$^1$.

• Theories typically define such states using gauge fields and deconfined quasiparticle excitations that emerge from a simple rule governing the local ground state of a frustrated magnet.
• For example, the '2-in-2-out' ice rule for dipole moments on a tetrahedron can lead to a quantum spin ice in rare-earth pyrochlores - a state described by a lattice gauge theory of quantum electrodynamics$^{2-4}$.
• However, f-electron ions often carry multipole degrees of freedom of higher rank than dipoles, leading to intriguing behaviours and 'hidden' orders$^{5-6}$.