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

Seo Won Lee, Kyoung Jin Lee

Research output: Contribution to journalArticle

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 languageEnglish
Article number5467630
Pages (from-to)2349-2352
Number of pages4
JournalIEEE Transactions on Magnetics
Volume46
Issue number6
DOIs
Publication statusPublished - 2010 Jun 1

Fingerprint

Torque
Microwaves
Induced currents
Magnetization

Keywords

  • Diffusive transport
  • Microwave oscillation
  • Spin transfer torque

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials

Cite this

Effect of angular dependence of spin-transfer torque on zero-field microwave oscillation in symmetric spin-valves. / Lee, Seo Won; Lee, Kyoung Jin.

In: IEEE Transactions on Magnetics, Vol. 46, No. 6, 5467630, 01.06.2010, p. 2349-2352.

Research output: Contribution to journalArticle

@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, {Kyoung Jin}",
year = "2010",
month = "6",
day = "1",
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, Kyoung Jin

PY - 2010/6/1

Y1 - 2010/6/1

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

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

U2 - 10.1109/TMAG.2010.2040146

DO - 10.1109/TMAG.2010.2040146

M3 - Article

AN - SCOPUS:77952795972

VL - 46

SP - 2349

EP - 2352

JO - IEEE Transactions on Magnetics

JF - IEEE Transactions on Magnetics

SN - 0018-9464

IS - 6

M1 - 5467630

ER -