Quest of electric field controlled spintronics in MnGe

With the seemly limit of scaling on CMOS microelectronics fast approaching, spintronics has received enormous attention as it promises next generation nanometric magneto-electronic devices; particularly, the electric field control of ferromagnetic transition in dilute magnetic semiconductor systems offers the magneto-electronic devices a potential for low power consumption and low variability. In this paper, we first review the current efforts on the development of Mn-doped Ge (MnGe) magnetic materials, followed by an analysis of MnGe thin films grown by molecular beam epitaxy. Then we show that with zero and one dimension quantum structures, superior magnetic properties of MnGe compared with bulk films can be obtained. More importantly, we demonstrate a field controlled ferromagnetism in these MnGe nanostructures at 50 K. The controllability of ferromagnetism in this material system is a major step towards the Ge-based spintronic devices.