Magnon thermal Hall effect via emergent SU(3) flux on the antiferromagnetic skyrmion lattice

Abstract

Complexity of quantum phases of matter is often understood theoretically by using gauge structures, as is recognized by the $${{\mathbb{Z}}}_{2}$$ Z 2 and U(1) gauge theory description of spin liquids in frustrated magnets. Anomalous Hall effect of conducting electrons can intrinsically arise from a U(1) gauge expressing the spatial modulation of ferromagnetic moments or from an SU(2) gauge representing the spin-orbit coupling effect. Similarly, in insulating ferro and antiferromagnets, the magnon contribution to anomalous transports is explained in terms of U(1) and SU(2) fluxes present in the ordered magnetic structure. Here, we report thermal Hall measurements of MnSc2S4 in an applied field up to 14 T, for which we consider an emergent higher rank SU(3) flux, controlling the magnon transport. The thermal Hall coefficient takes a substantial value when the material enters a three-sublattice antiferromagnetic skyrmion phase, which is in agreement with the linear spin-wave theory. In our description, magnons are dressed with SU(3) gauge field, which is a mixture of three species of U(1) gauge fields originating from the slowly varying magnetic moments on these sublattices.

Magnetoresistive Evidence of Degeneracy in Nanomagnets Obtained by Electrodeposition Technique

“…Specifically, they have been pointed out as interesting materials for advances in the area of magnetricity [2], which involves the transport of magnetic charges, just as electricity involves the transport of electrical charges through associated currents, but with much lower dissipation loss. Other interesting applications are in magnonics, a research field that studies the application and effect of spin wave propagation in nanomagnetic materials [3], and neuromorphic computing systems [4]. Those materials can be found in the form of rare-earth insulating oxides, such as the pyrochlores Dy 2 Ti 2 O 7 and Ho 2 Sn 2 O 7 , being characterized by having a highly macroscopically degenerate ground state that follows Pauling's ice rule [5].…”