Antiferromagnetic-ferromagnetic homostructures with Dirac magnons in van der Waals magnet CrI$_3$

Autor: Schneeloch, John A., Daemen, Luke, Louca, Despina
Rok vydání: 2023
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevB.109.024409
Popis: Van der Waals (vdW) Dirac magnon system CrI$_3$, a potential host of topological edge magnons, orders ferromagnetically (FM) (T$_C=61$ K) in the bulk, but antiferromagnetic (AFM) order has been observed in nanometer thick flakes, attributed to monoclinic (M) type stacking. We report neutron scattering measurements on a powder sample where the usual transition to the rhombohedral (R) phase was inhibited for a majority of the structure. Elastic measurements (and the opening of a hysteresis in magnetization data on a pressed pellet) showed that an AFM transition is clearly present below $\sim$50 K, coexisting with the R-type FM order. Inelastic measurements showed a decrease in magnon energy compared to the R phase, consistent with a smaller interlayer magnetic coupling in M-type stacking. A gap remains at the Dirac point, suggesting that the same nontrivial magnon topology reported for the R phase may be present in the M phase as well.
Comment: includes supplement
Databáze: arXiv