The basis of microelectronics is the manipulation of charged electrons. The basis of spintronics is the conversion of electricity to magnetism and vice versa in order to manipulate the spin of electrons. Both approaches can produce transistors and other elements used in electronics (computers et al), but spintronics has advantages: Unlike the charge of electrons, the spin of electrons does not require a continuous electrical current. In other words, the spin is retained when the power is off. As a corollary, setting the spin of electrons requires only a short burst of energy (magnetic) to set the spin, which means spintronic devices require less power than conventional semiconductor devices. Also, spintronic devices don’t require semiconductor materials and can be made from common materials such as copper, aluminum – and now graphene.
Graphene is carbon (how very common) that has many unexpected electrical properties due to its form (one carbon atom thick sheets) and atomic configuration (the carbon atoms are arranged in a hexagonal “honeycomb” pattern). Since it was first popularized and exploited by Andre Geim and Konstantin Novoselov, who received the 2010 Nobel Prize in Physics for their work, graphene has revealed one amazing capability after another. This time Geim and Novoselov are back to demonstrate the ability of graphene to magnetize in a way useful for spintronics.
Published in the journal Science 15 April 2011, paywall [Giant Nonlocality Near the Dirac Point in Graphene] the research team found a new way to apply a relatively weak magnetic field to graphene that causes the spin direction (up or down) to flow in a direction perpendicular to electric current – magnetizing the graphene. By placing the graphene on a layer of boron nitride, they discovered that the graphene magnetism extends over a fairly large distance (in the parlance of the physics trade that means ‘macroscopic,’ or distances that could be noted by the human eye). This ‘larger’ form of spintronics overcomes one of the difficulties with previous materials of manipulating the spin on the atomic (nano) scale.
Keep in mind that this research is a demonstration of graphene’s properties under very special conditions. It’s a long way from what amounts to a proof of concept to the actual application in a production electronics device. Nevertheless, this is yet another property of graphene with enormous potential. The real test will be whether graphene and spintronics can be made: 1. Reliable, 2. Scalable and 3. Competitive.
Also in SciTechStory: Graphene spintronics studies show promise