TY - JOUR
T1 - MRAM device incorporating single-layer switching via rashba-induced spin torque
AU - Guo, Jie
AU - Tan, Seng Ghee
AU - Jalil, Mansoor Bin Abdul
AU - Eason, Kwaku
AU - Lua, Sunny Yan Hwee
AU - Rachid, Sbiaa
AU - Meng, Hao
N1 - Funding Information:
The support of the ASTAR SERC Grant No. 092 101 0060 (R-398-000-061-305) is gratefully acknowledged.
PY - 2011/10
Y1 - 2011/10
N2 - We designed and modeled a nonvolatile memory device that utilizes the Rashba spin-orbit coupling (SOC) to write data onto a free ferromagnetic (FM) layer and uses the tunneling magnetoresistive (TMR) effect for data read-back. The magnetic RAM (MRAM) device consists of a free (switchable) FM multilayer stack, in which a large internal electric field is induced at the interfaces between the oxide and the FM layer. In the FM layer, data writing by magnetization switching occurs via the Rashba-induced spin torque, while the data reading process in the system could be fulfilled via the current-perpendicular-to-plane TMR response. A general equation of motion for the local moments has been obtained by formally deriving the SU(2) spin-orbit gauge field arising due to SOC and the critical current density is estimated to be 1.2× 108 A/cm2. Micromagnetic simulations were performed to demonstrate the Rashba-induced switching mechanism. By choosing or fabricating alloys with a lower magnetocrystalline anisotropy and enhancing the Rashba coupling strength via surface or interfacial engineering, the critical current may be further reduced to well below 107 A/cm2, a level that may enable the practical realization of a single-layer Rashba-induced magnetization switching memory.
AB - We designed and modeled a nonvolatile memory device that utilizes the Rashba spin-orbit coupling (SOC) to write data onto a free ferromagnetic (FM) layer and uses the tunneling magnetoresistive (TMR) effect for data read-back. The magnetic RAM (MRAM) device consists of a free (switchable) FM multilayer stack, in which a large internal electric field is induced at the interfaces between the oxide and the FM layer. In the FM layer, data writing by magnetization switching occurs via the Rashba-induced spin torque, while the data reading process in the system could be fulfilled via the current-perpendicular-to-plane TMR response. A general equation of motion for the local moments has been obtained by formally deriving the SU(2) spin-orbit gauge field arising due to SOC and the critical current density is estimated to be 1.2× 108 A/cm2. Micromagnetic simulations were performed to demonstrate the Rashba-induced switching mechanism. By choosing or fabricating alloys with a lower magnetocrystalline anisotropy and enhancing the Rashba coupling strength via surface or interfacial engineering, the critical current may be further reduced to well below 107 A/cm2, a level that may enable the practical realization of a single-layer Rashba-induced magnetization switching memory.
KW - Magnetic RAM (MRAM)
KW - Rashba spin-orbit interaction
KW - spin transfer torque (STT)
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U2 - 10.1109/TMAG.2011.2158634
DO - 10.1109/TMAG.2011.2158634
M3 - Article
AN - SCOPUS:80053522560
SN - 0018-9464
VL - 47
SP - 3868
EP - 3871
JO - IEEE Transactions on Magnetics
JF - IEEE Transactions on Magnetics
IS - 10
M1 - 6027645
ER -