A research team has demonstrated the realization of sextuple polarization states and state switching in antiferroelectric CuInP₂S₆ films. The study shows that these films can be stabilized into double, quadruple, and sextuple polarization states, with the sextuple state being reversibly tunable into the quadruple or double states. The team also found that mutual state switching can be achieved through moderate electric field modulation. First-principles calculations revealed that the different polarization states arise from the presence of single, double, and triple ferroelectric domains with antiferroelectric interdomain coupling and Cu ion migration. These findings offer promising platforms for developing multistate ferroelectric devices and have transformative implications for other non-volatile materials. The study highlights the potential of two-dimensional (2D) ferroelectrics to overcome the thickness limitations of traditional ferroelectric materials, enabling higher-order polarization states. The research team observed that the number of discrete polarization states in ferroelectric oxides has not exceeded four, but recent advances in 2D ferroelectrics have enabled the realization of higher-order states. The team demonstrated quadruple polarization states in CuInP₂S₆-In₄/₃P₂S₆ mixed-phase samples and four polarization states in 3R-MoS₂ thin films. These results suggest that higher-order polarization states can be achieved in 2D ferroelectrics, which could have significant applications in non-Boolean nanoelectronics. The team successfully demonstrated robust sextuple polarization states in vdW CuInP₂S₆ films, which can be reversibly tuned into quadruple or double states. The study also showed that mutual state switching can be achieved via moderate electric field modulation. The team proposed an innovative mechanism to explain the stabilization of sextuple polarization states and their mutual state switching, involving vertically stacked and antiferroelectrically coupled domains and Cu ion migration. These findings provide a new platform for developing multistate ferroelectric devices and have transformative implications for other non-volatile materials. The study also highlights the importance of understanding the underlying mechanisms of polarization states in ferroelectric materials for the development of advanced non-volatile memory technologies.A research team has demonstrated the realization of sextuple polarization states and state switching in antiferroelectric CuInP₂S₆ films. The study shows that these films can be stabilized into double, quadruple, and sextuple polarization states, with the sextuple state being reversibly tunable into the quadruple or double states. The team also found that mutual state switching can be achieved through moderate electric field modulation. First-principles calculations revealed that the different polarization states arise from the presence of single, double, and triple ferroelectric domains with antiferroelectric interdomain coupling and Cu ion migration. These findings offer promising platforms for developing multistate ferroelectric devices and have transformative implications for other non-volatile materials. The study highlights the potential of two-dimensional (2D) ferroelectrics to overcome the thickness limitations of traditional ferroelectric materials, enabling higher-order polarization states. The research team observed that the number of discrete polarization states in ferroelectric oxides has not exceeded four, but recent advances in 2D ferroelectrics have enabled the realization of higher-order states. The team demonstrated quadruple polarization states in CuInP₂S₆-In₄/₃P₂S₆ mixed-phase samples and four polarization states in 3R-MoS₂ thin films. These results suggest that higher-order polarization states can be achieved in 2D ferroelectrics, which could have significant applications in non-Boolean nanoelectronics. The team successfully demonstrated robust sextuple polarization states in vdW CuInP₂S₆ films, which can be reversibly tuned into quadruple or double states. The study also showed that mutual state switching can be achieved via moderate electric field modulation. The team proposed an innovative mechanism to explain the stabilization of sextuple polarization states and their mutual state switching, involving vertically stacked and antiferroelectrically coupled domains and Cu ion migration. These findings provide a new platform for developing multistate ferroelectric devices and have transformative implications for other non-volatile materials. The study also highlights the importance of understanding the underlying mechanisms of polarization states in ferroelectric materials for the development of advanced non-volatile memory technologies.