Ferroelectric Control of Spin Textures in Layered Hybrid Perovskites

TL;DR

This study demonstrates that layered hybrid perovskites exhibit switchable spin textures controlled by ferroelectric polarization, enabling electrical manipulation of spin states for potential spintronic applications.

Contribution

It reveals the coupling between ferroelectricity and spin textures in layered hybrid perovskites, showing polarization reversal can control spin orientation.

Findings

Robust in-plane ferroelectric polarization stabilizes out-of-plane spin textures.

Polarization reversal switches the spin orientation.

Materials exhibit sizable spin splittings at band edges.

Abstract

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)$_2$CsY$_2$X$_7$ (Y = Pb, Sn; X = I, Br) using density functional theory, Berry-phase polarization analysis, and effective $\boldsymbol{k \cdot p}$ modeling. Across all four members, we find indirect bandgaps with extrema near $\Gamma$, 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)$_2$CsY$_2$X$_7$ as a versatile materials platform where compositional design and ferroelectric switching jointly enable spintronic functionality.