Speaker
Description
Polar transition metal dichalgenides (TMDs) host electronic states with strong Rashba spin orbit interactions, yielding two spin-split Fermi surfaces with opposite spin chirality. Electrons of each chirality have an electron spin constrained perpendicularly to the electron momentum, and as a result the collective plasmon excitations of polar TMDs present themselves as coupled charge- and spin density waves. Here we demonstrate that at the interface between a polar TMD and an insulating ferrimagnet, the plasmon excitations strongly hybridize with the ferrimagnetic magnon excitations. Due to the inequivalence of magnetic sublattice sites, ferrimagnetic magnons carry a magnetic dipole moment without any external magnetic field, and are thus spin-polarised, leading to strong exchange-mediated coupling between plasmons and magnons. Moreover, we show that the hybrid plasmon-magnon modes are topologically non-trivial due to the phase winding of the coupling between magnons and plasmons, which is inherited from the spin-momentum locking of the electronic states.
| Field of Condensed Matter | Magnetism |
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