Fig. 1. Formation and classification of magnetic ordering. (a) Schematic of direct exchange, double exchange and super exchange between atomic magnetic moments; (b) classification of magnets according to ferromagnetic/antiferromagnetic coupling within/between magnetic atomic layers

Fig. 2. Structural diagrams of two types of antiferromagnetic materials. (a) Octahedral honeycomb configuration of chromium trihalide CrX₃^[35]; (b) rhombic and monoclinic phases of CrX₃^[44]; (c) hexagonal honeycomb configuration of transition metal phosphorus sulfur compound MPX₃^[21]; (d) ground-state magnetic structures of FePS₃, NiPS₃, and MnPS₃^[21]

Fig. 3. Multiple magneto-optical phenomena in antiferromagnetic thin film

Fig. 4. Birefringence and dichroism in magneto optic effect. (a) Influence of magnetic circular birefringence (MCB), magnetic circular dichroism (MCD), magnetic linear birefringence (MLB),and magnetic linear dichroism (MLD) on polarization of reflected light^[28]; (b) MLD comparison of FePS₃, NiPS₃,and MnPS₃^[21]; (c) temperature dependence of MLD in FePS₃^[21]; (d) anisotropy and polarization rotation of reflected light^[21]; (e) spectral response of MLD^[21]

Fig. 5. Magnetic photocurrent effect in CrI₃. (a) Schematic of four-layer CrI₃ graphene device^[94]; (b) differential reflection spectrum of CrI₃ and spectral response of photocurrent^[94]; (c) regulation of interlayer magnetic order (middle) on photocurrent (above) and tunneling current (below)^[94]; (d) circular polarization response characteristics of photocurrent in trilayer CrI₃^[94]; (e) regulation of circular-polarized degree of photocurrent by ferromagnetic/antiferromagnetic states^[94]

Fig. 6. Magneto-optic second harmonic and Raman spectra of MPX₃. (a) Temperature dependences of second harmonic emissions in FePS₃, NiPS₃ and MnPS₃^[80]; (b)temperature and polarization dependences of second harmonic emissions in MnPS₃ with different thicknesses^[80]; (c) Raman scattering spectra of bulk and monolayer NiPS₃^[73]; (d) effects of temperature and sample thickness on magnetic oscillation^[73]

Fig. 7. Electrical and pressure regulations of antiferromagnetic order. (a) Electric and magnetic field regulations of CrI₃ magnetic state reflected by MOKE signal^[105]; (b) ferromagnetic/antiferromagnetic state regulated by back and top gate voltages reflected by MCD signal under steady-state magnetic field^[105]; (c) linear correlation between MOKE signal and gate voltage under zero magnetic field^[105]; (d) schematic of in-plane stress control of MnPSe₃^[109]; (e) Néel vector orientated by stress direction, reflected by polarization-resolved second harmonic signal^[109]

Fig. 8. Magnetic control effect of ultrafast laser. (a) Schematic of laser-induced Mn₃Sn antiferromagnetic order quenching and detection^[71]; (b) spin dynamics with different incident angle configurations at room temperature ^[71]; (c) comparison of spin dynamics and transient absorption signals in Mn₃Sn^[71]; (d) schematic of experimental configuration for detection of NiPS₃ terahertz emission^[81]; (e) time-evolution terahertz electric fields caused by coherent magnon oscillation at different temperatures^[81]; (f) laser-induced transient antiferromagnetic metal state in NiPS₃^[81]

Fig. 9. Magnon dynamics induced by ultrafast laser. (a) Construction of electric control devices with bilayer CrI₃/monolayer WSe₂ heterostructure and schematic of interlayer charge transfer process^[141]; (b) magnon dynamics under different magnetic fields^[141]; (c) magnon frequency regulated by gate voltage^[141]; (d) magnon dynamics corresponding to optical absorption transition at different energy levels in NiPS₃^[143]

Fig. 10. Optical properties of excitons in CrI₃. (a) Excitonic emission with circular polarization characteristics of monolayer and bilayer CrI₃^[35]; (b) phonon modified electronic states related to excitons at different temperatures reflected by periodic Raman modes^[152]; (c) magnetic field correlation between Raman mode amplitude (above) and electron-phonon coupling intensity (below) ^[152]; (d) transition of electron-phonon coupling intensity near magnetic critical temperature^[152]

Fig. 11. Exciton effects of two types of two-dimensional antiferromagnets. (a) Narrow linewidth fluorescence emission characteristics of NiPS₃ excitons with different thicknesses^[22]; (b) temperature and polarization dependences of multilayer NiPS₃ exciton fluorescence^[32]; (c) temperature dependence of exciton fluorescence in CrSBr^[40]; (d) correlation between fluorescence and magnetic field in monolayer and bilayer CrSBr^[40]

Fig. 12. Strong magnon-phonon coupling in FePS₃. (a) Schematics of magnon, phonon and magnon-phonon strong coupling modes in classical model^[164]; (b) Raman spectra of FePS₃ and anti-cross characteristics of strong magnon-phonon coupling in 0-30 T magnetic field ^[164]; (c) comparison of polarization characteristics between pure phonon mode (left) and magnon-phonon coupling mode (right) controlled by magnetic field^[167]; (d) intensity contour maps corresponding to Fig.12(c)^[167]