Spintronics is an alternative paradigm for information processing in which the state variable is the spin angular momentum of the electronic carriers. The ability to exploit spin in semiconductors has rapidly progressed in recent years, with discovery of exciting new phenomena raising prospects for novel devices having new functionality. For example, spin injection into semiconductor at room temperature (Nature 462, 491 (2009)) and electric field manipulation of spin polarization in quantum structures (Nature materials 9, 133 (2010)). Much of the interest in semiconductor quantum structures drives from its higher mobility and its prospect of electric field manipulation of spin polarization, which is the aim of this project. While relevant for the development of a spin-transistor, this work will go well beyond that, aiming for new routes to control spins in semiconductor quantum devices. The experimental work includes the growth of ferromagnet/semiconductor heterostructures, nanofabrication in clean room, and magneto transport measurement of the spintronic devices. While performing experiments in this research field, the postdoc will have enough freedom to explore and invent his/her own ideas.