Room Temperature Planar Hall Transistor

Controlling the spin transport in solids electrically is central to the application of spintronics for the development of information technology1. Since the spin-transistor was proposed by Datta and Das in 1990s, due to the difficulties of spin injection and detection in semiconductors, until now there is still no efficient spin field effect transistor developed2-4. Recently, the spin Hall transistor based on two-dimensional electron gas has been demonstrated, in which the spins were generated optically rather than electrically in the semiconductor channel5. Here we report the tunability of the planar Hall resistance in ferromagnetic half metal Co2FeAl devices solely by piezo voltages from positive to negative and from negative to positive, which can be analogously used as the n-type and p-type field effect transistor, respectively. The magnetic NOT and NOR gates are demonstrated based on the Co2FeAl planar Hall transistors without external magnetic field at room temperature. Our demonstration can pave a way for the application of future spintronics, realizing both the information storage and processing using ferromagnetic materials.