Graphene steps towards spintronics with magnetic discovery
1 min read
University of Manchester scientists have found a way to make graphene magnetic, a move that could offer significant advances in the area of spintronics.
The team, part of a large international effort involving research groups from the US, Russia, Japan and the Netherlands, was led by Professor Andre Geim, who won the Nobel Prize in 2010 for his breakthrough experiments with the material graphene.
Not satisfied with what he had already achieved, Prof Geim and his collaborators set out to demonstrate another effect that involved quantum mechanics at ambient conditions. He believes the discovery will open a new chapter to the short history of graphene, this time in the field of spintronics.
"The key feature for spintronics is to connect the electron spin to electric current, as current can be manipulated by means routinely used in microelectronics," he explained. "It is believed that, in future spintronics devices and transistors, coupling between the current and spin will be direct, without using magnetic materials to inject spins as it is done at the moment."
According to Geim, so far this route has only been demonstrated by using materials with so called spin orbit interaction, in which tiny magnetic fields created by nuclei affect the motion of electrons through a crystal. "The effect is generally small which makes it difficult to use," he said.
As such, the team found a new way to interconnect spin and charge by applying a relatively weak magnetic field to graphene. They found that this caused a flow of spins in the direction perpendicular to electric current, making the graphene sheet magnetised.
"The effect resembled the one caused by spin orbit interaction but is larger and can be tuned by varying the external magnetic field," said Geim. "We also showed that graphene placed on boron nitride was an ideal material for spintronics because the induced magnetism extended over macroscopic distances from the current path without decay."
The team believes its discovery will offer numerous opportunities for redesigning current spintronics devices and making new ones such as spin based transistors. Prof Geim continued: "The holy grail of spintronics is the conversion of electricity into magnetism or vice versa. We can now offer a new mechanism, thanks to the unique properties of graphene. I imagine that many venues of spintronics will benefit from this finding."
