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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-3240
DTSTART:20140218T220000Z
DURATION:PT1H0M0S
DTSTAMP:20240319T021314Z
LAST-MODIFIED:20140121T212022Z
LOCATION:4274 Chamberlin Hall
SUMMARY:Emerging spin-orbit interaction driven phenomena in magnetic h
eterostructures\, Faculty Candidate Seminar\, Xin Fan\, University of
Deleware
DESCRIPTION:Charge and spin are both intrinsic properties of electrons
. While the charge property has been ubiquitously deployed in every el
ectronic device\, the potential of spin property is only realized sinc
e 1980s. The manipulation of spins in electronic devices\, known as sp
intronics\, has resulted in many practical applications. The first gen
eration of spintronics devices\, such as spin valves and magnetic tunn
el junctions\, uses the magnetization to tune the flow of electrons an
d has already revolutionized the development of computer hard disk dri
ve. The new generation of spintronics devices uses electrons flow to c
ontrol the magnetization. This electrical control on magnetization wil
l lead to new generation of fast and nonvolatile magnetic random acces
s memory. Such manipulation of magnetization becomes more feasible rec
ently due to emerging spin-orbit interaction driven phenomena that ari
se from the interior of the materials as well as the interface in inve
rsion symmetry-breaking heterostructures.
\nThe Spin-orbit interac
tion is a relativistic effect describing the coupling between a partic
leaEuroTMs spin and motion. It lifts the spin-dependent degeneracy of
electronaEuroTMs motion in a solid. The related phenomena have been in
tensively studied in semiconductors over the past decades. Very recent
ly\, it has been shown that the spin-orbit interaction in metals can b
e orders stronger than that in conventional semiconductors. It is demo
nstrated that an electric current through a heavy metal/ferromagnetic
metal bilayer can efficiently control the magnetization of the ferroma
gnetic layer.
\nAlthough the phenomena have been successfully demo
nstrated\, the microscopic detail of the spin-orbit interaction in the
metallic bilayer is still unclear. The major question is whether the
dominating spin-orbit interaction is from the spin Hall effect in the
heavy metal itself (bulk effect) or the Rashba effect at the interface
(interface effect). In this talk\, I will firstly introduce both elec
trical and optical methods that I developed to determine the magnetic
torques generated from the spin-orbit interaction. Then I will show th
e co-existence of interface and bulk contributions in the samples unde
r study. The result suggests that both the selection of the heavy meta
l and the engineering of the interface are crucial for the control of
the magnetization. In the end\, I will discuss the challenges and pote
ntial researches in this area.
URL:https://www.physics.wisc.edu/events/?id=3240
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