TY - JOUR
T1 - Spin-transfer-torque-induced zero-field microwave oscillator using a magnetic easy cone state
AU - Jang, Peong Hwa
AU - Lee, Seo Won
AU - Lee, Kyung Jin
N1 - Funding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) ( 2011-0027905 , NRF- 2011-0028163 ).
Publisher Copyright:
© 2016 Elsevier B.V.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2016/12/1
Y1 - 2016/12/1
N2 - Current-induced spin-transfer torque can induce magnetization precession in gigahertz ranges, which enables various microwave devices. In most cases, this current-induced precession requires an additional external magnetic field, which is detrimental for device applications. In this work, we show that the current-induced precession is realized even without an external field when the magnetic layer has conical magnetization, caused by the second order easy-axis magnetic anisotropy. We theoretically derive the oscillation frequency and output power and confirm their validity by macrospin simulations. We find that the ratio of the second to the first anisotropy constants is key to determine the maximum frequency and power. Our results will be helpful for the applications of microwave devices utilizing spin-transfer torques and provide a design rule of such devices.
AB - Current-induced spin-transfer torque can induce magnetization precession in gigahertz ranges, which enables various microwave devices. In most cases, this current-induced precession requires an additional external magnetic field, which is detrimental for device applications. In this work, we show that the current-induced precession is realized even without an external field when the magnetic layer has conical magnetization, caused by the second order easy-axis magnetic anisotropy. We theoretically derive the oscillation frequency and output power and confirm their validity by macrospin simulations. We find that the ratio of the second to the first anisotropy constants is key to determine the maximum frequency and power. Our results will be helpful for the applications of microwave devices utilizing spin-transfer torques and provide a design rule of such devices.
KW - Spin-torque oscillator
KW - Spin-transfer torque
UR - http://www.scopus.com/inward/record.url?scp=84988978732&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84988978732&partnerID=8YFLogxK
U2 - 10.1016/j.cap.2016.09.004
DO - 10.1016/j.cap.2016.09.004
M3 - Article
AN - SCOPUS:84988978732
SN - 1567-1739
VL - 16
SP - 1550
EP - 1553
JO - Current Applied Physics
JF - Current Applied Physics
IS - 12
ER -