The layering of crystals into a superlattice yields a nanoscale magnetic structure of twisting, swirling spin orientations, revealed from red to blue, that deflect electrons, revealed as white dots. Credit: Adam Malin/ORNL, U.S. Dept. of Energy
Scientists found a method for layering different crystals with atomic accuracy to manage the size of resulting magnetic quasi-particles called skyrmions. This technique might advance high-density information storage and quantum magnets for quantum details science.
In normal ferromagnets, magnetic spins align up or down. Yet in skyrmions, they twist and swirl, forming distinct shapes like small porcupines or small twisters.
The small linked magnetic structures might innovate high-density information storage, for which size does matter and should be little. The Oak Ridge National Laboratory-led task produced skyrmions as little as 10 nanometers – 10,000 times thinner than a human hair.
“The way we design and synthesize the superlattice creates the atomic-scale magnetic interactions responsible for twisting the spins,” stated physicist Elizabeth Skoropata, who co-led the research study with John Nichols, both previously of ORNL.
ORNL’s Ho Nyung Lee included, “Our finding demonstrates how to precisely engineer interfaces in oxide quantum heterostructures to create nanometer-sized skyrmions.”
Reference: “Interfacial tuning of chiral magnetic interactions for big topological Hall results in LaMnO3/SrIrO3 heterostructures” by Elizabeth Skoropata, John Nichols, Jong Mok Ok, Rajesh V. Chopdekar, Eun Sang Choi, Ankur Rastogi, Changhee Sohn, Xiang Gao, Sangmoon Yoon, Thomas Farmer, Ryan D. Desautels, Yongseong Choi, Daniel Haskel, John W. Freeland, Satoshi Okamoto, Matthew Brahlek and Ho Nyung Lee, 3 July 2020, Science Advances.
DOI: 10.1126/sciadv.aaz3902
