In a discovery that could pave the way for faster, more powerful computing devices, researchers have clocked the fastest possible electrical switching in the naturally magnetic material magnetite.
Performed by researchers from the US Department of Energy's (DOE) SLAC National Accelerator Laboratory, the scientists used the facility's Linac Coherent Light Source (LCLS) X-ray in order to determine that it only takes 1 trillionth of a second to flip the on-off electrical switch in samples of magnetite, placing it thousands of times faster than those currently in use.
"This breakthrough research reveals for the first time the 'speed limit' for electrical switching in this material," Roopali Kukreja, a materials science researcher at SLAC and Stanford University and a lead author of the study, said in a press release.
Using the LCLS the researchers were also able to learn how the electronic structure of the sample rearranged into non-conducting "islands" surrounded by electrically conducting regions that began forming just hundreds of quadrillionths of a second after a laser pulse struck the sample.
Based on these results the group was able to gain a clearer sense of how such conducting and non-conducting states can not only coexist but collaborate to form electrical pathways in next-generation generation transistors.
First, the scientists started with hitting each sample with a visible-light laser. This fragmented the material's structure at an atomic scale and rearranged it to form the islands they observed. This blast was shortly followed by an ultrabright, ultrashort X-ray pulse that allowed researchers to study the timing and details of changes in the sample excited by the initial laser strike, for the first time.
Next, by adjusting the interval of the X-ray pulses ever so slightly, they were able to precisely measure how long it took the material to shift from a non-conducting to an electrically conducting state -- all the while observing the structural changes that occurred during this switch.
For decades, scientists have worked to resolve this electrical structure at the atomic level. Then, just last year, another research team identified its building blocks as "trimerons," which are formed by three iron atoms that lock in the charges.
Such laid a foundation in interpreting results from the LCLS experiment, the authors of the new study explained.
And nor is the story over yet: given that the magnetite had to be cooled to minus 190 degrees Celsius to lock its electrical charges in place, the researchers say their next step is to study more complex materials and room-temperature applications.
Furthermore, future experiments will aim to identify exotic compounds and test new techniques to induce the switching and tap into other properties that are superior to modern-day silicon transistors, according to the scientists who add they have already conducted follow-up studies focusing on a hybrid material that exhibits similar ultrafast switching properties at near room temperature, making it a better candidate for commercial use than magnetite.