The 69th JSAP Spring Meeting 2022

Presentation information

Oral presentation

10 Spintronics and Magnetics » 10.3 Spin devices, magnetic memories and storages

[24p-E202-9~17] 10.3 Spin devices, magnetic memories and storages

Thu. Mar 24, 2022 4:00 PM - 6:30 PM E202 (E202)

Yoichi Shiota(Kyoto Univ.), Koyama Tomohiro(阪大)

4:15 PM - 4:30 PM

[24p-E202-10] Field-free spin-orbit torque magnetization switching in a perpendicularly magnetized (Ga,Mn)As single layer

〇(P)Miao JIANG1, Chenda Wang1, Shinobu Ohya1,2,3, Masaaki Tanaka1,2 (1.EEIS, Univ. of Tokyo, 2.CSRN, Univ. of Tokyo, 3.IEI, Univ. of Tokyo)

Keywords:field-free SOT switching, semiconductor, single layer

Nowadays, magnetic random access memory (MRAM) is proposed as one of the most promising next-generation memory technologies. For further improving the writing performance, the integration density and the efficiency, current-induced spin-orbit torque (SOT) magnetization switching has been achieved in a ferromagnet single layer with a perpendicular magnetic anisotropy (PMA). By injecting an in-plane charge current, the spins induced by the internal effective fields in the single layer can exert a torque on the magnetic moment and reverse it. However, to achieve a deterministic magnetization switching in a magnetic system with PMA, a small in-plane external magnetic field Hext is generally necessary to break the symmetry, which limits the scalability of the SOT-MRAM devices. Therefore, achieving the field-free SOT magnetization switching in a ferromagnet single layer is strongly required because it is promising for obtaining both the high efficiency and good scalability of MRAM devices.
Here, we report a successful field-free SOT switching in a (Ga,Mn)As single layer by engineering a tilted anisotropy axis and a Mn distribution gradient along the growth direction. Our findings will advance the development of highly-efficient MRAM with better scalability.