A team of scientists working at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) has confirmed a special property known as “chirality—which potentially could be exploited to transmit and store data in a new way—in nanometers-thick samples of multilayer materials that have a disordered structure.
While most electronic devices rely on the flow of electrons’ charge, the scientific community is feverishly searching for new ways to revolutionize electronics by designing materials and methods to control other inherent electron traits, such as their orbits around atoms and their spin, which can be thought of as a compass needle tuned to face in different directions.
These properties, scientists hope, can enable faster, smaller, and more reliable data storage by facilitating spintronics—one facet of which is the use of spin current to manipulate domains and domain walls. Spintronics-driven devices could generate less heat and require less power than conventional devices.
In the latest study, detailed in the May 23 online edition of the journal Advanced Materials, scientists working at Berkeley Lab’s Molecular Foundry and Advanced Light Source (ALS) confirmed a chirality, or handedness, in the transition regions—called domain walls—between neighboring magnetic domains that have opposite spins.
Scientists hope to control chirality—analogous to right-handedness or left-handedness—to control magnetic domains and convey zeros and ones as in conventional computer memory.
The samples were composed of an amorphous alloy of gadolinium and cobalt, sandwiched between ultrathin layers of platinum and iridium, which are known to strongly impact neighboring spins.
Modern computer circuits commonly use silicon wafers based on a crystalline form of silicon, which has a regularly ordered structure. In this latest study, the material samples used in the experiments were amorphous, or noncrystalline, which means their atomic structure was disordered.
thumbnail courtesy of Lawrence Berkeley National Laboratory