Figure 8.

Comparison between tunnelling differential conductance spectra between Gr/CrI₃/Gr and Gr/CrBr₃/Gr devices in a magnetic field applied out-of-plane of the magnetic film for CrI₃ sample and in-the-plane of the magnetic film for CrBr₃ sample. For both materials, narrow low energy resonances appear, which are dispersive in the magnetic field. The color maps demonstrating the dependence of the differential conductance for (a, b) Gr/CrI₃/Gr and (c) Gr/CrBr₃/Gr devices illustrate the evolution of such resonances. The quantitative parameters describing the magnonic states, i.e., their zero-field energy and the slope ΔE/ΔB can be extracted based on the linear fits to the evolution of the energy of the resonances in the magnetic field (b, d). Panels (a) and (b) are adapted with permission from ref (14). Copyright 2018 AAAS. Panels (c) and (d) are adapted with permission from ref (131). Copyright 2018 Springer Nature.