Discovery Principles and Materials for Symmetry-Protected Persistent Spin Textures with Long Spin Lifetimes

Persistent spin textures (PST) in solid-state materials arise from a unidirectional spin-orbit field in momentum space and offer a route to deliver the necessary long carrier spin lifetimes utilized in future quantum microelectronic devices. Nonetheless, few bulk materials host PST owing to crystal symmetry and chemical requirements with even fewer experimentally demonstrated examples. This scarcity makes both PST materials discovery and performance assessment challenging. Here we demonstrate that bulk persistent spin textures exist in the family of layered A₃B₂O₇ oxides and that a persistent spin helix (PSH) occurs over a large region of the Brillouin zone—a feature essential to experimental realization. By solving the spin diffusion equations in the strong coupling limit and using the PST performance criteria we formulate herein, we find that the spin lifetime of the PSH is ~63ns in Sr₃Hf₂O₇—substantially larger than that predicted (~10 ns) and demonstrated experimentally (~600 ps) in GaAs/AlGaAs quantum wells. Last, we use group theory analysis and electronic structure calculations to formulate general discovery principles to identify PST in more materials.