Strain engineering a persistent spin helix with infinite spin lifetime

TL;DR

This paper demonstrates the discovery and design of persistent spin textures in certain materials, enabling long spin lifetimes crucial for quantum electronics, by leveraging symmetry analysis and electronic structure calculations.

Contribution

It introduces a general approach to identify PSTs in complex materials without relying on mirror symmetry, expanding the range of candidate materials.

Findings

PSTs can be realized in polar point groups with odd mirror operations.

Materials with large electric polarizations can host PSTs without special crystalline symmetries.

The approach broadens the scope for designing materials with long spin lifetimes.

Abstract

Persistent spin textures (PSTs) in solid-state materials arise from a unidirectional spin-orbit field in momentum space and offer a route to deliver long carrier spin lifetimes sought for future quantum microelectronic devices. Nonetheless, few three-dimensional materials are known to host PSTs owing to crystal symmetry and chemical requirements. There are even fewer examples demonstrated experimentally. Here we report that high-quality persistent spin textures can be obtained in the polar point groups containing an odd number of mirror operations. We use representation theory analysis and electronic structure calculations to formulate general discovery principles to identify PSTs hidden in known complex ternary layered and perovskite structures with large electric polarizations. We then show some of these materials exhibit PSTs without requiring any special crystalline symmetries. This finding removes the limitation imposed by mirror-symmetry protected PSTs that has limited compound discovery. Our general design approach enables the pursuit of persistent spin helices in materials exhibiting the $C_{3v}$ crystal class adopted by many quantum materials exhibiting large Rashba coefficients.