Antiferromagnetic-configuration–dependent high harmonic generation in bilayer CrI3

Abstract

Bilayer CrI3 accommodates both interlayer antiferromagnetic (AFM) and intralayer ferromagnetic couplings. Different alignments of intralayer ferromagnetic orders would lead to almost degenerate AFM configurations, which are insensitive to conventional techniques such as VSM and magneto-optical Kerr effect. Here, we demonstrate high harmonic generation (HHG) as a feasible means to detect the AFM configurations in bilayer CrI3 with AB and stacking orders. When the intralayer magnetic moments are aligned along the z-axis, the AB stacked bilayer CrI3 cancels the 3n-order harmonics under the circularly polarized laser field. However, the stacked bilayer contains both even and odd harmonic. The 3n-order harmonics are recovered as the intralayer magnetic moments of AB bilayer are in-plane aligned. For an in-plane linearly polarized laser field, the stacking bilayer with the magnetic moments along the x-axis contains both the even and odd harmonics in each component. However, when the magnetic moments are along the y-axis, the perpendicular component of HHG cancels out for the linearly polarized laser field along the x-axis. More interestingly, when the linearly polarized laser field is along the y-axis, the parallel component includes only the odd harmonics while the perpendicular component contains only the even harmonics. Our study provides HHG as a potential tool to detect AFM configurations.