In this proposal a new electric field based approach for the control of magnetization dynamics is discussed. The advantage of using electric fields compared to magnetic fields is twofold: (i) electric fields are easy to confine in nano-structures (screening), and (ii) no current flow is required which may allow for the development of new spintronic devices with ultra low power consumption.
Physically the application of an electric field to an ultrathin ferromagnetic material gives rise to modification of the wave-function overlap at the interface between a ferromagnetic metal and a dielectric. This electronic tuning causes a modified occupation of the d-orbitals at the interface and leads to electrically induced anisotropies. Hence external electric fields generate internal magnetic fields. Due to the modified orbital moment also a large voltage induced effect on the Gilbert damping is expected in magnetization dynamic experiments. In principle these fields can be applied even on ultrafast time scales. This will be explored when rf-electric fields are used to drive internal magnetic fields in the GHz frequency range to generate spin-waves. Furthermore this technique will be used to excite monochromatic spin-waves with wave-vectors well in the exchange dominated regime in order to study their propagation properties.
I propose to use the spin-wave Doppler effect in order to break the intrinsic mirror symmetry required in for four-magnon scattering processes. In this way the resonance saturation may be tuned electrically to much larger values. Moreover electrically driven surface acoustic waves will be used to generate spin-waves which will be manipulated by an electric current using the spin-wave Doppler effect.
The research described in the proposal is likely to have a large impact as a shift to electric field controlled spintronic devices is favorable on small length scales. In addition the power consumption of these devices may be reduced significantly.
Call for proposal
See other projects for this call
Funding SchemeERC-SG - ERC Starting Grant