Tuneable interface exchange for optical magnetisation control- Dr Theo Trypiniotis (TFM)

Beyond studies of spin dependent transport which have traditionally dominated the field of spintronics, an increasing number of investigations of more ‘exotic’ spin related phenomena are being reported in the last few years. In this talk I will present the extension of our work in spin transport, into the use of spin accumulation for the optical control of magnetisation.

We can routinely use optical spin orientation in III -V semiconductors as a reliable spin source for spin transport investigations. We have recently successfully combined the above with ferromagnetic resonance (FMR) measurements on epitaxial ferromagnetic-metal/semiconductor interfaces. The optically controlled spin polarised carrier population at the interface affects the ferromagnet magnetisation via an interface exchange interaction the signature of which is measured in the FMR response. We have demonstrated an effective exchange field of the order of tens of Gauss at room temperature, which offers a new method for the optical control of magnetization.