Straining graphene creates strongest pseudo-magnetic fields ever sustained in a lab
Graphene, the one-atom-thick material made up of a honeycomb lattice of carbon atoms, has produced yet another in a long list of experimental surprises. Its remarkable properties have already got researchers excited regarding its applications for faster computers, cheaper and more efficient batteries and vastly higher density mass data storage. Now researchers have reported the creation of pseudo-magnetic fields far stronger than the strongest magnetic fields ever sustained in a laboratory – just by putting the right kind of strain onto a patch of graphene. The breakthrough could have far reaching scientific applications.
“We have shown experimentally that when graphene is stretched to form nanobubbles on a platinum substrate, electrons behave as if they were subject to magnetic fields in excess of 300 tesla, even though no magnetic field has actually been applied,” says Michael Crommie, a faculty senior scientist in the Materials Sciences Division at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and a professor of physics at the University of California at Berkeley who headed a multi-institutional team of researchers who made the discovery. “This is a completely new physical effect that has no counterpart in any other condensed matter system.”
Crommie notes that “for over 100 years people have been sticking materials into magnetic fields to see how the electrons behave, but it’s impossible to sustain tremendously strong magnetic fields in a laboratory setting.” The current record is 85 tesla for a field that lasts only thousandths of a second. When stronger fields are created, the magnets blow themselves apart.
The ability to make electrons behave as if they were in magnetic fields of 300 tesla or more – just by stretching graphene – offers a new window on a source of important applications and fundamental scientific discoveries going back over a century. This is made possible by graphene’s electronic behavior, which is unlike any other material’s.