The 80th JSAP Autumn Meeting 2019

Presentation information

Oral presentation

Code-sharing session » 【CS.8】 Code-sharing Session of 10.1, 10.2, 10.3 & 10.4

[20p-E216-1~7] 【CS.8】 Code-sharing Session of 10.1, 10.2, 10.3 & 10.4

Fri. Sep 20, 2019 1:30 PM - 3:15 PM E216 (E216)

Eiji Shikoh(大阪市大)

3:00 PM - 3:15 PM

[20p-E216-7] Racetrack memory by design: enhanced current induced domain wall motion through interfacial engineering

〇(D)Yicheng Guan1, Xilin Zhou1, Tianping Ma1, Stuart S. P. Parkin1 (1.Max-Planck Society)

Keywords:domain wall motion, interfacial engineering

Racetrack memory which is a novel innately three-dimensional memory device promises a storage-class memory with the low cost per bit of magnetic disk drives but the high performance and reliability of conventional solid-state memories. The data in racetrack memory is encoded as a pattern of magnetic domains along a portion of the nanowire which is composed of the perpendicular magnetized ferromagnetic layers such as Co/Ni and the heavy metal such as Pt thin film stack. Current-induced domain wall (DW) motion in this perpendicular magnetized ferromagnet (FM)/heavy metal (HM) multilayer films has been intensively researched since its potential for realizing the memory devices with higher speed, compacity and low energy consumption. Driven by the spin-orbit torque generated from the spin-orbit coupling from the interfaces, the Néel type DW stabilized by the interfacial Dzyaloshinskii-Moriya interaction could move along the nanowire in response to sequences of current pulses with fast speed and fixed chirality. The energy efficiency and highly scalable current-induced DW motion have been the main research focus for the realization of the racetrack memory devices.
Here, in this work, we demonstrate an enhanced current-induced DW motion through interfacial engineering by introducing atomic thin ‘dusting’ layers of 4d and 5d metal at the FM/HM interface in the magnetic stacks. We also apply this interfacial engineering approach to a synthetic antiferromagnetic structure which further increases the domain wall motion efficiency with considerably lower threshold current density which decreased by a factor of 3 and simultaneously substantially higher velocity which increased by a factor of 2. Significant modifications of magnetic properties could be realized with this novel technique and more detailed inner correlations of interfacial interactions are discussed in this work.