Current-induced domain wall motion: Comparison of STT and SHE

TY - JOUR

T1 - Current-induced domain wall motion

T2 - Comparison of STT and SHE

AU - Chureemart, J.

AU - Sampan-a-pai, S.

AU - Boonchui, S.

AU - Chantrell, R. W.

AU - Chureemart, P.

N1 - Funding Information: P.C. gratefully acknowledges the funding from Mahasarakham University and National Research Council of Thailand (NRCT) under Grant No. NRCT5-RSA63014. J. C. would like to thank the support from Faculty of Science (Grant year 2019). © 2021 Elsevier B.V. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy.

PY - 2021/7/1

Y1 - 2021/7/1

N2 - In this work, the current-induced domain wall (DW) motion driven by spin Hall effect (SHE) is theoretically investigated via an atomistic model. The SHE is taken into account in the atomistic model as a Slonczewski torque term. We first consider a bilayer system consisting of a ferromagnetic layer (FM) adjacent to a heavy metal (HM). To study the effect of spin Hall angle and FM thickness on DW motion in perpendicularly magnetized FM, an in-plane current is injected into HM. The results show that the critical current density, DW velocity and DW displacement strongly depend on the spin Hall angle and thickness of FM. To demonstrate the efficiency of SOT, we also study the DW motion driven by spin-transfer torque (STT) in a FM/NM/FM system by injecting a charge current perpendicularly to the plane of the structure. The DW velocity and DW displacement of two cases are compared. At the same current density, it is clearly observed that the DW in the presence of SOT is more easily moved with higher velocity and DW displacement. In addition, the critical current density of SHE driven case is smaller compared with spin torque case. To move the DW with the velocity of 100 m/s, the injected current density required for the STT case could be 10 times as high as the SHE case. The proposed model can be used to optimize all factors for spintronic device design with low power consumption, fast speed and high endurance such as the DW-based devices and the perpendicularly magnetized SOT-MRAM.

AB - In this work, the current-induced domain wall (DW) motion driven by spin Hall effect (SHE) is theoretically investigated via an atomistic model. The SHE is taken into account in the atomistic model as a Slonczewski torque term. We first consider a bilayer system consisting of a ferromagnetic layer (FM) adjacent to a heavy metal (HM). To study the effect of spin Hall angle and FM thickness on DW motion in perpendicularly magnetized FM, an in-plane current is injected into HM. The results show that the critical current density, DW velocity and DW displacement strongly depend on the spin Hall angle and thickness of FM. To demonstrate the efficiency of SOT, we also study the DW motion driven by spin-transfer torque (STT) in a FM/NM/FM system by injecting a charge current perpendicularly to the plane of the structure. The DW velocity and DW displacement of two cases are compared. At the same current density, it is clearly observed that the DW in the presence of SOT is more easily moved with higher velocity and DW displacement. In addition, the critical current density of SHE driven case is smaller compared with spin torque case. To move the DW with the velocity of 100 m/s, the injected current density required for the STT case could be 10 times as high as the SHE case. The proposed model can be used to optimize all factors for spintronic device design with low power consumption, fast speed and high endurance such as the DW-based devices and the perpendicularly magnetized SOT-MRAM.

KW - Domain wall motion

KW - Spin-Hall effect

KW - Spin-transfer torque

UR - http://www.scopus.com/inward/record.url?scp=85102132876&partnerID=8YFLogxK

U2 - 10.1016/j.jmmm.2021.167838

DO - 10.1016/j.jmmm.2021.167838

M3 - Article

AN - SCOPUS:85102132876

SN - 0304-8853

VL - 529

JO - Journal of Magnetism and Magnetic Materials

JF - Journal of Magnetism and Magnetic Materials

M1 - 167838

ER -