Electric-field control of magnetization, Jahn-Teller distortion and orbital ordering in ferroelectric ferromagnets*

Controlling the direction of the magnetization by an electric field in multiferroics that are both ferroelectric and strong ferromagnetic will open the doors to the design of next generation of spintronics and memory devices. Unfortunately, this has never been achieved so far mostly because these materials are very scarce and/or may not have a large enough magnetoelectric coupling. Here, using first-principles simulations, we report the discovery that PbTiO₃/LaTiO₃ (PTO/LTO) superlattice does possess such highly-desired control, as evidenced by the electric-field-induced rotation of 90° and even full possible reversal of its magnetization in some cases. Moreover, such "wunderbar'' systems also exhibit Jahn-Teller distortions, as well as orbital orderings, that are switchable by electric field, therefore making PTO/LTO of importance for the tuning of electronic properties too. Other possible materials possessing such couplings are also discussed, which further renders the presently reported electric controls to be a new general strategy to tune various properties of functional materials.