“Graphene is an excellent medium for spin transport at room temperature, due to its low atomic mass,” said Saroj Dash, group leader and an associate professor at Chalmers. “However, an unsolved challenge was to control the spin current at ambient temperature.”
The research team has shown that it is possible to manipulate the spin properties of graphene electrically in a controlled manner at room temperature. “Controlling the flow of spin currents in a transistor-like manner is a decade old dream and the missing link towards all-electrical spin logic applications,” said researcher Andre Dankert. “Researchers have been working for almost 10 years to understand the spin transport properties of various layered materials and how they can be tuned to achieve this goal. Our work is an important milestone in the field of spintronics.”
Graphene has been shown to transport spin over long distances by several Flagship Groups. By combining graphene with another layered material in which spin doesn’t last as long, it is possible to produce a device which operates like a spin field-effect transistor.
Dash added: “By combining graphene, where spin lasts for nano seconds, with molybdenum disulphide, where spin only lasts for picoseconds, you can control where the spin can go by using a gate voltage – essentially you can create a spin switch. Importantly, we show in this research a particular materials mix which enables this spin-switch to work at room temperature.”
While many layered materials are said to be promising for spintronics, the team says the bigger goal is to create novel spin phenomena by stacking different layers with complementary properties.