Ferroelectric polarization control of magnetic anisotropy in PbZr0.2Ti0.8O3 /

The interfacial coupling between the switchable polarization and neighboring magnetic order makes ferroelectric/ferromagnetic composite structures a versatile platform to realize voltage control of magnetic anisotropy. We report the nonvolatile ferroelectric field effect modulation of the magnetocrystalline anisotropy (MCA) in epitaxial $\mathrm{PbZ}{\mathrm{r}}_{0.2}\mathrm{T}{\mathrm{i}}_{0.8}{\mathrm{O}}_{3}$ (PZT)/$\mathrm{L}{\mathrm{a}}_{0.8}\mathrm{S}{\mathrm{r}}_{0.2}\mathrm{Mn}{\mathrm{O}}_{3}$ (LSMO) heterostructures grown on (001) $\mathrm{SrTi}{\mathrm{O}}_{3}$ substrates. Planar Hall effect measurements show that the in-plane magnetic anisotropy energy in LSMO is enhanced by about 22% in the hole accumulation state compared to the depletion state, in quantitative agreement with our first-principles density functional theory calculations. Modeling the spin-orbit coupling effect with second-order perturbation theory points to the critical role of the $d$-orbital occupancy in controlling MCA. Our work provides insights into the effect of ferroelectric polarization on the magnetic anisotropy at the composite multiferroic interfaces, paving the path for their implementation into high-performance, low-power spintronic applications.