Scientists have the achieved a speed record for electrical switching in magnetite, a naturally magnetic mineral. According to a news release from the U.S. Department of Energy's SLAC National Accelerator Laboratory, the findings could influence changes in the small transistors that regulate the flow of electricity across silicon chips, allowing for quicker, more powerful computers.
Researchers using SLAC's Linac Coherent Light Sources X-ray laser discovered that it takes only 1 trillionth of a second to flip the on-off electrical switch in samples of magnetite. According to the researchers, this is thousands of times quicker than in transistors now in use.
Lead author Roopali Kukreja, a materials science researchers at SLAC and Stanford University, says these findings show for the first time the "speed limit" for electrical switching in magnetite.
This study also demonstrated to scientists how the electronic structure of the sample reorganized into non-conducing "islands" encompassed by electrically conducing regions, which started to form just hundreds of a quadrillionths of a second after a laser pulse hit the sample. The study reveals how such conducting and non-conducting states can exist together and develop electrical pathways in next-generation transistors.
Researchers first struck each sample with a visible-light laser, which splintered the material's electronic structure at an atomic scale, reorganizing it to create the islands. The laser pulse was followed soon after by an X-ray pulse that gave researchers the chance to examine the timing and details of alterations in the sample agitated by the first laser strike.
By modifying the interval of the X-ray pulse, researchers accurately determined how long it took the material to change from a non-conducting to an electrically conducing state, and noted the structural alterations during this switch in states.
In 2012, another research team had pinpointed the building blocks of this electrical structure as "trimerons." That discovery offered important information for making sense of the findings from the LCLS experiment.
According to the news release, the magnetite had to be cooled to minus 190 degrees Celsius to secure its electrical charges in place, so the next research project will examine more complex materials and potential room-temperature applications. Scientists hope to describe unusual compounds and test novel techniques to encourage the switching and exploit other properties that can be used in next-generation transistors.
According to Hermann Dürr, the principal investigator of the LCLS experiment, there is a major push to look beyond modern semiconductor transistors by utilizing novel materials to answer the calls for smaller and faster computers.
The study's findings are described in greater detail in the journal Nature Materials.
