Spin texture evolution of Rashba splitting under pressure: a case study of inorganic nitride perovskite crystals

Abstract

Spin–orbit coupling (SOC) effects in non-centrosymmetric systems lead to a uniform spin configuration in momentum space known as persistent spin texture (PST). The PST has been predicted to support an extraordinarily long spin lifetime of carriers, which is promising for spintronic applications. Using density functional theory, we report the existence of PST in nitrogen-based perovskite (CeTaN₃), a non-centrosymmetric ferroelectric material with a spontaneous polarization of 5.6 μC cm⁻² along the [100] direction. Our calculations showed that CeTaN₃ is a direct band gap (0.436 eV) semiconductor and exhibits PST in both the conduction and valence bands. The calculated Rashba parameter was 0.399 eV Å (0.282 eV Å) for the conduction (valence) band. A comprehensive investigation of the stability of CeTaN₃ was performed by calculating its elastic constants, reaction decomposition enthalpy, and phonon dispersion. All three methods showed that CeTaN₃ is stable. We also investigated the effects of hydrostatic pressure on the spin splitting of the bands. We found that CeTaN₃ preserved the PST up to 6 GPa and the splitting of the bands disappeared at 8 GPa. The present study paves the way for using external pressure as a prime factor in tuning not-yet-synthesized perovskite materials suitable for spintronic and optoelectronic applications.