Ferroelectric control of the Néel vector in L10-type antiferromagnetic films

How to efficiently manipulate the N\'eel vector of antiferromagnets by electric methods is one of the major focuses in current antiferromagnetic spintronics. In this work, we investigated the ferroelectric control of magnetism in antiferromagnetic $L10\text{\ensuremath{-}}\mathrm{Mn}\mathrm{Pt}/\mathrm{Ba}\mathrm{Ti}{\mathrm{O}}₃$ bilayer structures by using first-principles calculation. We studied the effect of ferroelectric polarization reversal on magnetic crystalline anisotropy (MCA) of $L10$-MnPt films with different interface structures. Our results predict a large perpendicular MCA in $L10$-MnPt films with Pt-O interface, and an in-plane MCA with Mn-O interface when they are interfaced with ferroelectric $\mathrm{Ba}\mathrm{Ti}{\mathrm{O}}₃$. In addition, the magnitude of MCA for both interfaces can be modulated efficiently by the polarization reversal of $\mathrm{Ba}\mathrm{Ti}{\mathrm{O}}₃$. The ferroelectric control of MCA has been analyzed based on second order perturbation theory, and it can be mainly attributed to the ferroelectric polarization driven redistribution of Pt-$5d$ orbital occupation around Fermi energy. Especially, for the Mn-O interface, the N\'eel vector can be switched between in-plane [100] and [110] directions, or even from in plane to out of plane at certain film thickness by reversing ferroelectric polarization. Our results may provide a nonvolatile concept for ferroelectric control of N\'eel vector in $L10$ antiferromagnets, which could stimulate experimental investigations on magnetoelectric effect of antiferromagnets and promote its applications in low-power consumption spintronic memory devices.