All-Electric Spintronics through Surface/Interface Effects
Spintronics is an emerging area of nanoscale electronics involving the spin injection, transport, modulation and detection, and so on. Very recently, a new research branch, that is, all-electric spintronics, which requires spin manipulation via electric means, has received much focus. To eventually realize the practical application of tuning spin states electrically, understanding the mechanisms responsible for the magnetoelectric coupling is both fundamental and crucial. Although the mechanism is quite simple in physics, its magnetoelectric response appears to be quite large. The coupling between elastic components of the magnetic constituents and the piezoelectric ones through the strain effect is undoubtedly important. The interface bonding induced magnetoelectric effect mainly comes from ferroelectric displacements at the interface between ferroelectric and ferromagnetic constituents under the electric polarization. For a ferromagnetic metal, due to the well-known spin-dependent screening effect, that is, the spin-up and spin-down electrons will have quite different responses to electric field penetrating into the ferromagnet.