Fig. 1
From: Generating high-order optical and spin harmonics from ferromagnetic monolayers
High-order harmonic generation in ferromagnetic materials. a An intense laser pulse excites a ferromagnetic iron monolayer and generates high-order harmonics. The harmonic has spin signature on the spectrum and can be dispersed in the crystal momentum space, so the harmonic peak can be assigned to a unique transition between occupied and unoccupied states. Higher-order harmonics are more sensitive to the band structure change than lower-order ones, thus making HHG an ideal tool for spin-resolved detection. b Brillouin zone of a simple orthorhombic structure. c Two film orientations—Fe(110) and Fe(001)—are placed in the ab (or xy) plane
