First-principles Study of Rashba Spin Splitting at Strained SrTiO3(001) Surfaces

TL;DR

This study uses first-principles calculations to explore how compressive strain induces large Rashba spin splittings in SrTiO3(001) ultra-thin films, revealing significant spin-orbit effects relevant for spintronics.

Contribution

It provides the first detailed theoretical analysis of Rashba spin splitting in strained SrTiO3 surfaces, highlighting the role of polarization and surface states.

Findings

Large Rashba spin splittings observed in strained SrTiO3 films.

Localized surface states exhibit giant Rashba coefficients over 100 meV·Å.

Sheet carrier density comparable to LaAlO3/SrTiO3 heterostructures.

Abstract

We investigated the Rashba spin splittings in a compressive-strained SrTiO$_3$(001) ultra thin-film using first-principles calculations. The effect of the polarization due to the compressive strain leads to the 2DEG with large Rashba spin splittings, where the sheet carrier density is of the same order of magnitude as that of the heterostructure LaAlO$_3$/SrTiO$_3$ ($\sim10^{14}$ cm$^{-2}$). Some localized surface states (SSs) show the giant Rashba coefficient $\alpha_R$ larger than 100 meV$\cdot$\AA.