Rashba dominated spin-splitting in the bulk ferroelectric oxide perovskite KIO3

TL;DR

This study uses ab initio calculations to analyze Rashba spin-splitting in ferroelectric KIO3, revealing phase-dependent effects and spin-reversal upon polarization switching, with implications for spintronic applications.

Contribution

It provides the first detailed ab initio analysis of Rashba spin-splitting in ferroelectric KIO3, highlighting the roles of linear and cubic terms and polarization control.

Findings

Significant spin-splitting at CBm and VBM in R3m and R3c phases

Linear Rashba terms explain VBM splitting; cubic terms affect CBm

Spin orientation reverses with polarization switching

Abstract

The momentum-dependent Rashba and Dresselhaus spin-splitting has gained much attention for its highly promising applications in spintronics. In the present work, ab initio density functional theory calculations are performed to study the spin-splitting effect in ferroelectric oxide perovskite KIO3. Our calculations are additionally supported by symmetry adapted two-band k.p Hamiltonian. Non-negligible spin-splitting effect is observed at conduction band minimum (CBm) and valence band maximum (VBM) for rhombohedral R3m and R3c phases. Linear Rashba terms successfully explain the splitting at VBM. However, cubic terms become important in realizing spin-orientation near CBm. Our results show the enhancement in Rashba parameters on tuning the ferroelectric order parameter. Further, we have observed reversal of spin-orientation on switching the direction of polarization.