Scientists closer to developing graphene spintronic devices

WASHINGTON - Physicists from the City University of Hong Kong and the University of Science and Technology of China have taken a huge step toward the development of useful graphene spintronic devices.

Graphene, a two-dimensional crystalline form of carbon, has the breaking strength 200 times greater than steel.

However, Spintronic devices are being hotly pursued because they promise to be smaller, more versatile, and much faster than today’s electronics.

“There is strong research interest in spintronic devices that process information using electron spins, because these novel devices offer better performance than traditional electronic devices and will likely replace them one day,” said Kwok Sum Chan, of the City University of Hong Kong.

“Graphene is an important material for spintronic devices because its electron spin can maintain its direction for a long time and, as a result, information stored isn’t easily lost,” said Chan.

It is, however, difficult to generate a spin current in graphene, which would be a key part of carrying information in a graphene spintronic device. Chan and colleagues came up with a method to do just that.

It involves using spin splitting in monolayer graphene generated by ferromagnetic proximity effect and adiabatic (a process that is slow compared to the speed of the electrons in the device) quantum pumping.

They can control the degree of polarization of the spin current by varying the Fermi energy (the level in the distribution of electron energies in a solid at which a quantum state is equally likely to be occupied or empty), which they say is very important for meeting various application requirements.

The findings were presented in the American Institute of Physics’ Applied Physics Letters. (ANI)