Modeling of magnetoelectric effect for advanced spintronic applications

Spintronics is a novel field of electronics that uses the spin of electrons or the magnetization of thin films instead of charge in memory or logic computation devices. A key issue of spintronics is the energy-efficient control of the magnetization in such devices. Current device concepts are often based on the control of the magnetization by currents, for example via generated magnetic fields or recently discovered effects, such as spin-transfer torque or spin-orbit torque. However, such techniques are typically not very energy-efficient and it would be very desirable to control the magnetization by electric fields instead. In principle, this can be done by the magnetoelectric effect, which couples electric fields to the magnetization. This effect is currently strongly considered to be included in future generations of low-power spintronic devices.

​Magnetoelectric effects naturally occur in multiferroic materials but much stronger strain-induced magnetoelectric coupling can be observed in composite materials consisting of piezoelectric and magnetostrictive materials. The application in spintronic devices requires a detailed understanding of the geometry (e.g. the relative directions of the electric field and the magnetization) as well as thermal fluctuations on the magnetization dynamics. In this thesis, the student will perform simulations to study the magnetoelectric coupling in different geometries and different material systems. The goal of the thesis is to develop efficient strategies to control the magnetization orientation and switching by the magnetoelectric effect, as well as to assess the voltage generated by the magnetization rotation via inverse effect. The work will be in close collaboration with experimentalists working on integration of magnetoelectrics into spintronic devices for exploratory logic.