Spin-orbit effects in ferroelectric PbTiO3 under tensile strain

J. Gosteau (1) , Rémi Arras (1) , P. Chen (2) , H. Zhao (2) , Charles Paillard (3) , Laurent Bellaiche (2)

1 CEMES-MEM - Matériaux et dispositifs pour l'Electronique et le Magnétisme
2 Institute for nanosciences and engineering and physics departement [University of Arkansas]
3 SPMS - Laboratoire Structures, Propriétés et Modélisation des solides

We report a study based on first-principles calculations complemented by a tight-binding approach and a k⋅p model of the spin-orbit effects in epitaxially strained PbTiO3. The imposed biaxial tensile strain allows us to rotate the electrical polarization of PbTiO3 from out-of-plane to in-plane directions through structural phase transitions between a tetragonal, monoclinic, and orthorhombic phase. It is found that Ti d-state conduction bands exhibit two strong Rashba-like spin-splitting parameters of (1) 0.39 eV Å at a tensile strain η=1.55% due to a polarization rotation in the monoclinic phase and (2) 1.08 eV Å under large tensile strain of 3.8% due to band anticrossing in the orthorhombic phase. Remarkably, we also identified the presence of a quasipersistent spin texture for the band with a dyz−zx character in the orthorhombic phase. We then conclude that using strain could be an interesting way to tune the spin-orbit effects in ferroelectric materials with technological interests.

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Physique Numérique [physics.comp-ph]

J. Gosteau, Rémi Arras, P. Chen, H. Zhao, Charles Paillard, et al.. Spin-orbit effects in ferroelectric PbTiO3 under tensile strain. Physical Review B, 2021, 103 (2), pp.024416. ⟨10.1103/PhysRevB.103.024416⟩. ⟨hal-03295044⟩