Effect of angular dependence of spin-transfer torque on zero-field microwave oscillation in symmetric spin-valves

Seo Won Lee; Kyung Jin Lee

doi:10.1109/TMAG.2010.2040146

Effect of angular dependence of spin-transfer torque on zero-field microwave oscillation in symmetric spin-valves

Seo Won Lee, Kyung Jin Lee

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

11 Citations (Scopus)

Abstract

We numerically investigate effect of the angular dependence of spin-transfer torque (STT) on current-induced precession mode in symmetric spin-valve structures where two ferromagnets are free to move. Two spin-valve structures with NiFe and Co as ferromagnets are studied, which show considerably different angular dependence of STT. We find that the zero-field microwave oscillation occurs in symmetric spin-valve structures. Precession frequency can reach around 10 GHz and decreases with increasing current. In contrast to a spin-valve structure with a single free layer, the blue shift is not observed due to highly nonlinear coupling of two magnetizations. We find that more symmetric angular dependence of STT allows the magnetic excitation at a lower current and provides a more monotonous increase of output power.

Original language	English
Article number	5467630
Pages (from-to)	2349-2352
Number of pages	4
Journal	IEEE Transactions on Magnetics
Volume	46
Issue number	6
DOIs	https://doi.org/10.1109/TMAG.2010.2040146
Publication status	Published - 2010 Jun

Bibliographical note

Funding Information:
This work was supported by the Degree of Research Center (DRC) Program funded by the Korea Research Council of Fundamental Science and Technology (KRCF).

Keywords

Diffusive transport
Microwave oscillation
Spin transfer torque

ASJC Scopus subject areas

Electronic, Optical and Magnetic Materials
Electrical and Electronic Engineering

Access to Document

10.1109/TMAG.2010.2040146

Cite this

@article{4f0268ac0be848bfa5d184f0dd215da7,

title = "Effect of angular dependence of spin-transfer torque on zero-field microwave oscillation in symmetric spin-valves",

abstract = "We numerically investigate effect of the angular dependence of spin-transfer torque (STT) on current-induced precession mode in symmetric spin-valve structures where two ferromagnets are free to move. Two spin-valve structures with NiFe and Co as ferromagnets are studied, which show considerably different angular dependence of STT. We find that the zero-field microwave oscillation occurs in symmetric spin-valve structures. Precession frequency can reach around 10 GHz and decreases with increasing current. In contrast to a spin-valve structure with a single free layer, the blue shift is not observed due to highly nonlinear coupling of two magnetizations. We find that more symmetric angular dependence of STT allows the magnetic excitation at a lower current and provides a more monotonous increase of output power.",

keywords = "Diffusive transport, Microwave oscillation, Spin transfer torque",

author = "Lee, {Seo Won} and Lee, {Kyung Jin}",

note = "Funding Information: This work was supported by the Degree of Research Center (DRC) Program funded by the Korea Research Council of Fundamental Science and Technology (KRCF).",

year = "2010",

month = jun,

doi = "10.1109/TMAG.2010.2040146",

language = "English",

volume = "46",

pages = "2349--2352",

journal = "IEEE Transactions on Magnetics",

issn = "0018-9464",

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

number = "6",

}

TY - JOUR

T1 - Effect of angular dependence of spin-transfer torque on zero-field microwave oscillation in symmetric spin-valves

AU - Lee, Seo Won

AU - Lee, Kyung Jin

N1 - Funding Information: This work was supported by the Degree of Research Center (DRC) Program funded by the Korea Research Council of Fundamental Science and Technology (KRCF).

PY - 2010/6

Y1 - 2010/6

N2 - We numerically investigate effect of the angular dependence of spin-transfer torque (STT) on current-induced precession mode in symmetric spin-valve structures where two ferromagnets are free to move. Two spin-valve structures with NiFe and Co as ferromagnets are studied, which show considerably different angular dependence of STT. We find that the zero-field microwave oscillation occurs in symmetric spin-valve structures. Precession frequency can reach around 10 GHz and decreases with increasing current. In contrast to a spin-valve structure with a single free layer, the blue shift is not observed due to highly nonlinear coupling of two magnetizations. We find that more symmetric angular dependence of STT allows the magnetic excitation at a lower current and provides a more monotonous increase of output power.

AB - We numerically investigate effect of the angular dependence of spin-transfer torque (STT) on current-induced precession mode in symmetric spin-valve structures where two ferromagnets are free to move. Two spin-valve structures with NiFe and Co as ferromagnets are studied, which show considerably different angular dependence of STT. We find that the zero-field microwave oscillation occurs in symmetric spin-valve structures. Precession frequency can reach around 10 GHz and decreases with increasing current. In contrast to a spin-valve structure with a single free layer, the blue shift is not observed due to highly nonlinear coupling of two magnetizations. We find that more symmetric angular dependence of STT allows the magnetic excitation at a lower current and provides a more monotonous increase of output power.

KW - Diffusive transport

KW - Microwave oscillation

KW - Spin transfer torque

UR - http://www.scopus.com/inward/record.url?scp=77952795972&partnerID=8YFLogxK

U2 - 10.1109/TMAG.2010.2040146

DO - 10.1109/TMAG.2010.2040146

M3 - Article

AN - SCOPUS:77952795972

SN - 0018-9464

VL - 46

SP - 2349

EP - 2352

JO - IEEE Transactions on Magnetics

JF - IEEE Transactions on Magnetics

IS - 6

M1 - 5467630

ER -

Effect of angular dependence of spin-transfer torque on zero-field microwave oscillation in symmetric spin-valves

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this