Spin-torque effect on thermally excited magnetization fluctuation noise in tunneling magnetoresistive read heads

Yasushi Endo; Tetsuya Abe; Masahiro Yamaguchi

doi:10.1109/TMAG.2011.2155046

Spin-torque effect on thermally excited magnetization fluctuation noise in tunneling magnetoresistive read heads

Yasushi Endo, Tetsuya Abe, Masahiro Yamaguchi

ENG - Electrical Engineering

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

1 Citation (Scopus)

Abstract

The spin-torque (ST) effect on the thermally excited magnetization fluctuation noise (thermal mag-noise) in tunneling magnetoresistive (TMR) read heads is investigated in the GHz range using noise spectra. The strong noise spectral peak around 3.1 GHz is attributed to thermal mag-noise originating from the free layer. The peak intensity and linewidth strongly depend on both the external magnetic field and current density. These features demonstrate that the ST effect significantly influences the thermal mag-noise as the current density increases up to the critical current density. Additionally, it is speculated that the non-thermal fluctuation noise originating from ST in the TMR heads as well as in current perpendicular to plane giant magnetoresistive (CPP-GMR) heads is generated above a critical current of approximately 2.5× 10 ¹¹ A/m².

Original language	English
Article number	6028239
Pages (from-to)	3135-3138
Number of pages	4
Journal	IEEE Transactions on Magnetics
Volume	47
Issue number	10
DOIs	https://doi.org/10.1109/TMAG.2011.2155046
Publication status	Published - 2011 Oct

Keywords

Critical current density
TMR read head
magnetization fluctuation noise
spin-torque
thermal mag-noise

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Electrical and Electronic Engineering

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10.1109/TMAG.2011.2155046

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@article{a3183b142a024389a5357f752f996c4c,

title = "Spin-torque effect on thermally excited magnetization fluctuation noise in tunneling magnetoresistive read heads",

abstract = "The spin-torque (ST) effect on the thermally excited magnetization fluctuation noise (thermal mag-noise) in tunneling magnetoresistive (TMR) read heads is investigated in the GHz range using noise spectra. The strong noise spectral peak around 3.1 GHz is attributed to thermal mag-noise originating from the free layer. The peak intensity and linewidth strongly depend on both the external magnetic field and current density. These features demonstrate that the ST effect significantly influences the thermal mag-noise as the current density increases up to the critical current density. Additionally, it is speculated that the non-thermal fluctuation noise originating from ST in the TMR heads as well as in current perpendicular to plane giant magnetoresistive (CPP-GMR) heads is generated above a critical current of approximately 2.5× 10 11 A/m2.",

keywords = "Critical current density, TMR read head, magnetization fluctuation noise, spin-torque, thermal mag-noise",

author = "Yasushi Endo and Tetsuya Abe and Masahiro Yamaguchi",

note = "Funding Information: ACKNOWLEDGMENT This work was supported in part by the Storage Research Consortium (SRC).",

year = "2011",

month = oct,

doi = "10.1109/TMAG.2011.2155046",

language = "English",

volume = "47",

pages = "3135--3138",

journal = "IEEE Transactions on Magnetics",

issn = "0018-9464",

publisher = "Institute of Electrical and Electronics Engineers Inc.",

number = "10",

}

TY - JOUR

T1 - Spin-torque effect on thermally excited magnetization fluctuation noise in tunneling magnetoresistive read heads

AU - Endo, Yasushi

AU - Abe, Tetsuya

AU - Yamaguchi, Masahiro

N1 - Funding Information: ACKNOWLEDGMENT This work was supported in part by the Storage Research Consortium (SRC).

PY - 2011/10

Y1 - 2011/10

N2 - The spin-torque (ST) effect on the thermally excited magnetization fluctuation noise (thermal mag-noise) in tunneling magnetoresistive (TMR) read heads is investigated in the GHz range using noise spectra. The strong noise spectral peak around 3.1 GHz is attributed to thermal mag-noise originating from the free layer. The peak intensity and linewidth strongly depend on both the external magnetic field and current density. These features demonstrate that the ST effect significantly influences the thermal mag-noise as the current density increases up to the critical current density. Additionally, it is speculated that the non-thermal fluctuation noise originating from ST in the TMR heads as well as in current perpendicular to plane giant magnetoresistive (CPP-GMR) heads is generated above a critical current of approximately 2.5× 10 11 A/m2.

AB - The spin-torque (ST) effect on the thermally excited magnetization fluctuation noise (thermal mag-noise) in tunneling magnetoresistive (TMR) read heads is investigated in the GHz range using noise spectra. The strong noise spectral peak around 3.1 GHz is attributed to thermal mag-noise originating from the free layer. The peak intensity and linewidth strongly depend on both the external magnetic field and current density. These features demonstrate that the ST effect significantly influences the thermal mag-noise as the current density increases up to the critical current density. Additionally, it is speculated that the non-thermal fluctuation noise originating from ST in the TMR heads as well as in current perpendicular to plane giant magnetoresistive (CPP-GMR) heads is generated above a critical current of approximately 2.5× 10 11 A/m2.

KW - Critical current density

KW - TMR read head

KW - magnetization fluctuation noise

KW - spin-torque

KW - thermal mag-noise

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DO - 10.1109/TMAG.2011.2155046

M3 - Article

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JO - IEEE Transactions on Magnetics

JF - IEEE Transactions on Magnetics

IS - 10

M1 - 6028239

ER -

Spin-torque effect on thermally excited magnetization fluctuation noise in tunneling magnetoresistive read heads

Abstract

Keywords

ASJC Scopus subject areas

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