APS March Meeting 2015
Volume 60, Number 1
Monday–Friday, March 2–6, 2015;
San Antonio, Texas
Session Y28: Focus Session: Spin-Hall Effect III
8:00 AM–11:00 AM,
Friday, March 6, 2015
Room: 205
Sponsoring
Units:
GMAG DMP FIAP
Chair: Luqiao Liu, IBM Yorktown Heights
Abstract ID: BAPS.2015.MAR.Y28.10
Abstract: Y28.00010 : Quantifying Spin Hall and Rashba effect contributions to spin-orbit toque in magnetic bilayers
9:48 AM–10:24 AM
Preview Abstract
Abstract
Author:
John Q. Xiao
(Department of Physics and Astronomy, University of Delaware)
Electrical control of magnetism has been energized by recent observation of
spin-orbit torques in magnetic bilayers made of a heavy metal (HM) and
ferromagnet (FM). It has been demonstrated that the spin-orbit torques
driven by an in-plane current can switch magnetization, manipulate magnetic
domains and excite magnetization auto-oscillation. However, the microscopic
mechanism for the spin-orbit torques is still under debate. The question
being whether the dominating spin-orbit coupling (SOC) arises from the HM/FM
interface due to the Rashba effect or arises in the bulk of HM due to the
spin Hall effect, or a combination of the two. It has been theoretically
demonstrated that both the Rashba effect and the spin Hall effect generate a
field-like torque (T$_{\mathrm{SOF}})$ and damping-like torque
(T$_{\mathrm{SOT}})$ on the magnetization, with only quantitative
differences. Therefore, an accurate method to determine the
T$_{\mathrm{SOF}}$ and T$_{\mathrm{SOT}}$ with various thicknesses of the FM
and HM are needed. We present a newly developed, magneto-optic-Kerr-effect
based spin-orbit torque magnetometer that measures both T$_{\mathrm{SOF}}$
and T$_{\mathrm{SOT}}$, which can have both spatial and time resolution. We
observed both T$_{\mathrm{SOF}}$ and T$_{\mathrm{SOT}}$ are nonlocal and
does not require direct contact between FM and HM ...[1, 2]. By engineering
the interface which modifies the Rashba interaction, we are able to show the
co-existence of spin Hall and Rashba effect as well as quantify both
contributions to spin-orbit torques [1].\\[4pt]
[1] Fan, X., H. Celik, J. Wu, C. Ni, K.-J. Lee, V.O. Lorenz, and J.Q. Xiao,
\textit{Quantifying interface and bulk contributions to spin-orbit torque in magnetic bilayers.} Nature Communication, 2014. \textbf{January 9}: p. ncomms4042.\\[0pt]
[2] Fan, X., J. Wu, Y.P. Chen, M.J. Jerry, H.W. Zhang, and J.Q. Xiao,
\textit{Observation of the nonlocal spin-orbital effective field.} Nature Communications, 2013. \textbf{4, April 30}.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2015.MAR.Y28.10