Intrinsic Magnetic Edge States Revealed by Ultrafast Magneto-Optical Spectroscopy in MoTe₂ Nanoribbons

Understanding ultrafast spin dynamics in low-dimensional materials is crucial for advancing spintronic and quantum technologies. Here, we investigate the ultrafast magneto-optical response of MoTe₂ nanoribbons, where zigzag edge engineering induces localized magnetic states in an otherwise nonmagnetic material. The structural characterization and the polarization angle-resolved second-harmonic generation confirm the zigzag edge configuration, known to host edge-localized spin polarization. Using femtosecond time-resolved magneto-optical Kerr effect (tr-MOKE) and transient reflection spectroscopy, we resolve the spin and charge dynamics following optical excitation. The tr-MOKE dynamics strongly depend on the probe polarization with respect to the ribbon alignment, indicating the coupling between the ribbon edge state and the electromagnetic field from the probe pulse. These findings reveal that edge engineering in MoTe₂ nanoribbons provides a unique platform for manipulating spin at ultrafast timescales, paving the way toward edge state spintronic applications.