22 May 2019
Magnetic memory becomes easier to make
Published online 12 January 2014
Computer technology could become a whole lot faster through the use of magnetoresistive RAM (MRAM), an energy efficient, fast and long-term memory storage system, thanks to a collaboration between Saudi Arabia's King Abdullah University of Science and Technology (KAUST) and the National University of Singapore (NUS).
In MRAM, bits of information are flipped by changing the polarity of one of two magnetic plates separated by a thin insulating layer. It was recently shown that spin-orbit transfer torques, the transfer of angular momentum to a magnetized layer by the flow of a spin-polarized current, allow the manipulation of the magnetization by an in-plane current.
The magnetic plates used to study spin-orbit transfer torques must be thinner than 1 nanometre to work, and were difficult to make. However, in a paper published in Physical Review Letters, the team showed that a 20 nm thick cobalt-palladium magnetic multilayer, which is easier to fabricate, has even larger spin-transfer properties and could be used in MRAM technology.
"We will no longer need to wait for our computers or laptops to boot up," said NUS's Yang Hyunsoo, who led the study. "Storage space will increase, and memory will be enhanced so there will be no need to regularly hit the 'save' button as fresh data will stay intact even in the case of a power failure."
- Obata, K & Tatara, G. Current-induced domain wall motion in Rashba spin-orbit system. Phys. Rev. B. (2008) doi:10.1103/PhysRevB.77.214429
- Jamali, M. et al. Spin-Orbit Torques in Co/Pd Multilayer Nanowires. Physical Review Letters (2013) doi:10.1103/PhysRevLett.111.246602