Dual referenced composite free layer design optimization for improving switching efficiency of spin-transfer torque RAM

Roy Bell; Jiaxi Hu; R. H. Victora

doi:10.1063/1.4977493

Dual referenced composite free layer design optimization for improving switching efficiency of spin-transfer torque RAM

Roy Bell, Jiaxi Hu, R. H. Victora

Electrical and Computer Engineering

Research output: Contribution to journal › Article › peer-review

4 Scopus citations

Abstract

We present a detailed numerical analysis of switching efficiency for the recently proposed dual referenced composite free layer structure with respect to Gilbert damping. Low anisotropy assistive layers enable reduction of Gilbert damping and an increase of partial spin polarization within those low anisotropy layers - not feasible with single layer structures that require high anisotropy for thermal stability. When the damping of the soft layers is ultra-low, an efficiency (k_BT/μA) of 8.1 is achieved for the composite structure with perpendicular anisotropy. This represents an improvement of 286% and 913% relative to the state-of-the-art dual-referenced and conventional STT-RAM cells, respectively. Results for structures with longitudinal anisotropy are also presented. A linear calculation of the STT polarization pre-factor is also described that captures all reflections.

Original language	English (US)
Article number	055929
Journal	AIP Advances
Volume	7
Issue number	5
DOIs	https://doi.org/10.1063/1.4977493
State	Published - May 1 2017

Bibliographical note

Funding Information:
This work was supported in part by C-SPIN, one of six centers of STARnet, a Semiconductor Research Corporation program, sponsored by MARCO and DARPA. This work was also supported partially by the MRSEC Program under Contract No. DMR-0819885.

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abstract = "We present a detailed numerical analysis of switching efficiency for the recently proposed dual referenced composite free layer structure with respect to Gilbert damping. Low anisotropy assistive layers enable reduction of Gilbert damping and an increase of partial spin polarization within those low anisotropy layers - not feasible with single layer structures that require high anisotropy for thermal stability. When the damping of the soft layers is ultra-low, an efficiency (kBT/μA) of 8.1 is achieved for the composite structure with perpendicular anisotropy. This represents an improvement of 286% and 913% relative to the state-of-the-art dual-referenced and conventional STT-RAM cells, respectively. Results for structures with longitudinal anisotropy are also presented. A linear calculation of the STT polarization pre-factor is also described that captures all reflections.",

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N2 - We present a detailed numerical analysis of switching efficiency for the recently proposed dual referenced composite free layer structure with respect to Gilbert damping. Low anisotropy assistive layers enable reduction of Gilbert damping and an increase of partial spin polarization within those low anisotropy layers - not feasible with single layer structures that require high anisotropy for thermal stability. When the damping of the soft layers is ultra-low, an efficiency (kBT/μA) of 8.1 is achieved for the composite structure with perpendicular anisotropy. This represents an improvement of 286% and 913% relative to the state-of-the-art dual-referenced and conventional STT-RAM cells, respectively. Results for structures with longitudinal anisotropy are also presented. A linear calculation of the STT polarization pre-factor is also described that captures all reflections.

AB - We present a detailed numerical analysis of switching efficiency for the recently proposed dual referenced composite free layer structure with respect to Gilbert damping. Low anisotropy assistive layers enable reduction of Gilbert damping and an increase of partial spin polarization within those low anisotropy layers - not feasible with single layer structures that require high anisotropy for thermal stability. When the damping of the soft layers is ultra-low, an efficiency (kBT/μA) of 8.1 is achieved for the composite structure with perpendicular anisotropy. This represents an improvement of 286% and 913% relative to the state-of-the-art dual-referenced and conventional STT-RAM cells, respectively. Results for structures with longitudinal anisotropy are also presented. A linear calculation of the STT polarization pre-factor is also described that captures all reflections.

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Dual referenced composite free layer design optimization for improving switching efficiency of spin-transfer torque RAM

Abstract

Bibliographical note

How much support was provided by MRSEC?

Reporting period for MRSEC

Access

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MRSEC IRG-3: Hierarchical Multifunctional Macromolecular Materials

University of Minnesota MRSEC (DMR-0819885)

Cite this

Dual referenced composite free layer design optimization for improving switching efficiency of spin-transfer torque RAM

Abstract

Bibliographical note

How much support was provided by MRSEC?

Reporting period for MRSEC

Access

OpenUrl availability

Other files and links

Fingerprint

Projects

MRSEC IRG-3: Hierarchical Multifunctional Macromolecular Materials

University of Minnesota MRSEC (DMR-0819885)

Cite this