A collaborative research team led by Department of Physics Professor Kab- Jin Kim and Professor Kyung-Jin Lee of Korea University has developed a new technology that will significantly increase the capabilities of next-generation magnetic memory. The results of their research were published in the September 25 edition of Nature Materials, the world’s most cited scientific journal.
There are many flaws to the types of memory widely used today. For example, dynamic random-access memory (DRAM) and static random-access memory (SRAM) are volatile and not able to retain any data after the power is cut off. Flash memory is nonvolatile but slow. Finally, the hard disk drive is able to store large amounts of memory, but requires large amounts of power and is vulnerable to physical damage.
In order to overcome each of the aforementioned disadvantages, magnetic domain wall (DW) techniques are being developed for magnetic core technology. Through the placement of magnetic nanowires, DW techniques allow for nonvolatile, low-power memory devices through the reduction of all mechanical movements. However, due to the Walker Breakdown phenomenon, DW techniques are limited to a speed of a several hundred meters per second.
Professor Kim’s research team was able to overcome this limitation by noticing that all magnetic DW research had been conducted with ferromagnetic materials. Instead, by utilizing antiferromagnetic materials and satisfying certain conditions, they were able to find that the Walker Breakdown phenomenon could be avoided, allowing DW operation speed to reach 2 km/s at high temperatures.
There are high expectations for these new magnetic DW techniques as they provide a highly-integrated, power-efficient, and nonvolatile platform, which, if utilized in next-generation memory devices, could greatly surpass currently used hard disks. Professor Kim stated, “This research project was significant as we were able to discover a new physical phenomenon that occurs when the angular momentum of an antiferromagnetic material is zero,” and continued that he has “high expectations that next-generation memory devices will be available in the near future”.