Persistent spin texture in ferroelectric Hf0.5Zr0.5O2

Abstract

Persistent spin texture (PST) refers to the unidirectional spin configuration in momentum space and preserves the SU(2) spin rotation symmetry, which protects the spin coherence against the relaxation and renders an ultimately infinite spin lifetime. In this regard, it would be desirable to find high-quality quantum materials sustaining the intrinsic PST. Here, based on density-functional theory calculations, we show that the ferroelectric Hf0.5Zr0.5O2 sustains a PST over large area of Brillouin zone around the conduction band minimum, while the Rashba-type spin texture dominates around the valence band maximum. Based on the group-theoretical analysis, we construct an effective k·p Hamiltonian model and demonstrate that the PST arises from the significant anisotropy of spin splitting, which pins the spin–orbit field to certain direction. In addition, we elucidate the spin SU(2) symmetry for the discovered PST. Given the fact that Hf0.5Zr0.5O2 is compatible with silicon semiconductor technologies, our work discovers a high-quality oxide material sustaining the PST, which holds great promise for spin-orbitronic applications.