The study investigates atomic-level polarization reversal in sliding ferroelectric semiconductors, specifically van der Waals (vdW) layered yttrium-doped γ-InSe. The researchers directly observe real-time interlayer sliding along the armchair direction, leading to vertical polarization reversal. This sliding is driven by low-energy electron-beam illumination, suggesting low switching barriers. The team proposes a new sliding mechanism where two bilayer units slide towards each other simultaneously. Their findings provide insights into the polarization reversal process and offer potential for non-volatile storage and ferroelectric field-effect transistors. The study also highlights the role of Y-doping in enhancing ferroelectric properties and stabilizing the crystal structure. First-principles calculations support the observed sliding pathways and polarization reversal dynamics. These results advance the understanding of sliding ferroelectricity and its applications in high-speed, low-energy data processing devices.The study investigates atomic-level polarization reversal in sliding ferroelectric semiconductors, specifically van der Waals (vdW) layered yttrium-doped γ-InSe. The researchers directly observe real-time interlayer sliding along the armchair direction, leading to vertical polarization reversal. This sliding is driven by low-energy electron-beam illumination, suggesting low switching barriers. The team proposes a new sliding mechanism where two bilayer units slide towards each other simultaneously. Their findings provide insights into the polarization reversal process and offer potential for non-volatile storage and ferroelectric field-effect transistors. The study also highlights the role of Y-doping in enhancing ferroelectric properties and stabilizing the crystal structure. First-principles calculations support the observed sliding pathways and polarization reversal dynamics. These results advance the understanding of sliding ferroelectricity and its applications in high-speed, low-energy data processing devices.