Universal Design Principles for High-Quality Persistent Spin Textures

Persistent spin texture (PST) describes a unique spin-momentum locking in momentum space that maintains a uniform spin orientation through portions of the Brillouin zone (BZ), enabling exceptionally long spin lifetimes, which are essential for applications in spintronics. However, materials exhibiting large BZ regions of high-quality PST, characterized by minimal spin deviation and long spin lifetimes, remain scarce. Here, a universal model is introduced to capture the formation of superior PST regions arising from the interplay of spin–orbit fields at different k points. Within this framework, high-quality PSTs are identified in several systems belonging to various point groups. Notably, the nonpolar-chiral compound Na₂Sn₂O₃ exhibits a 0.02 Å⁻² high-quality PST region, which can be reversed by the switching of geometric chirality, while AgClO₄ (D_2d symmetry) exhibits a 0.016 Å⁻² PST region. Significantly, Na₂Sn₂O₃ and AgClO₄ are predicted to host persistent spin helices with spin lifetimes of 0.5–7.4 and 0.9–2.5 ns, respectively, among the longest reported for PST materials. In addition, both chemical substitution and the application of pressure are demonstrated as effective routes for engineering high-quality PST. Our findings not only establish a universal principle for high-quality PST, but also provide promising materials across various point groups for the next-generation spintronic devices.