2025/11/28 by Tyagi, Divyanshi, Bhattacharya, Saswata
Engineering · Materials Science · Physics and Astronomy · #Perovskite Materials and Applications #2D Materials and Applications #Advanced Condensed Matter Physics
paper · doi:10.48550/arxiv.2511.23038
Hybrid organic--inorganic perovskites with broken inversion symmetry provide a fertile ground for uncovering coupled spin-orbit and ferroelectric phenomena. Here, we investigate the layered family (PA)2CsY2X7 (Y = Pb, Sn; X = I, Br) using density functional theory, Berry-phase polarization analysis, and effective \boldsymbolk ⋅ p modeling. Across all four members, we find indirect bandgaps with extrema near Γ, sizable spin splittings at both band edges, and robust in-plane ferroelectric polarization that stabilizes out-of-plane persistent spin textures (PSTs). Crucially, polarization reversal switches the spin orientation, enabling electrical control of PSTs and thereby non-volatile manipulation of spin states. These results establish (PA)2CsY2X7 as a versatile materials platform where compositional design and ferroelectric switching jointly enable spintronic functionality.