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2009M7N9~11OP6GQRS0TUVBCWX!
Research
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Je = J!+ J"
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!100 ~ 1000 nm �©de@A�!
bc!�0R�*!d�ª«X¬!
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¹Kº¢!GMR or TMR�.Ò$%&'�/03�]!
100 Gb�S12K$�/inch2 34!
1 bit 56+100 nm 7Ú38!
90º·�!'º¿Fù!
3.5!"#$%&'()*!
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B?@!ù�F'!R0!
+!
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*+!
30%/year!
60%/year!
100%/year!
30%/year!
2345&!
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MR45&!
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ABC6'(7
TMR45&DTi-O, Al-OE!
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á=d�âãäå!�GMR�*YA!
!"#$%&'!*Yp!
HDD :;±<*CDkE4!The first major application
of nanotechnology
Peter Grünberg
(Germany)!
Albert Fert
(France)!
Giant Magnetoresistance (GMR)
HTUVWXYZ[VWXYZ\ ]I^_U`abcTdef
D)="ghijE
)=">?@GMR45&:kP!
Nobel week, December 2007!
ノーベル賞講演にて 12月8日
スウェーデンロイヤルアカデミーによるレセプションにて 12月7日
授賞式にて 12月10日
晩餐会にて 12月10日
FGk�·¸F!X¬!(1)!
CPP (Current-Perpendicular-to-Planel¤ÓHIJx) K!
PA(B)¢!"#rsL!
sub µm ~ µm 4Mxs!!"#
!
8Mxs!
¨de@A!A
ÿNO!
or
I
ÿNO!= PQ°¢$#QRd�âãäå�TMR�!
!77@7A¢á=d�âãäå�CPP-GMR�!
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MA
MB
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d�âãäå�MR�!*=VW!
!R
R PA$PB !"¢!
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Lateral structure�ÓXX¬�K!
VG
¨de@A! ¨de@A!
I
Je = J! + J" = 0
Js = J! - J" # 0
©de°!
!"#$%!
Non-local geometry
YZ�!"#1! !"#rsx1!
!"#tu!
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RÒS¢!"#$¿#�!À!
sub µm ~ µm
!"#$%&'!·¸F!*�e�[��"
\]�FG^_!
!"#rs�Spin polarization�!
!"#tu�!Spin injectionE!
!"#vw�!Spin relaxationE!
-a!$%äL`a!"#1�U[$P!
§bc��!"#1�1�a]!
6!"#rs()!
dwd�¢!
��x�*!"#rsL!
Fe: +0.40
Co: +0.35 Ni : +0.23
¨de!3d =ì@A!
*!"#rsL!
90˼ÀR; P = 1!
îF!¿0Ø@!7NiMnSb, Co2MnSi, Co2MnAl, etc.
=ì@Ae�Æ!7CrO2, Fe3O4, LSMO, etc.!
90˼ÀR¢îF!¿0Ø@!
C1b structure!
XYZ
L21 structure!
X2YZ (NiMnSb etc.)
(Co2MnSi, Co2MnGe etc.)
half-Heusler full-Heusler
Co2MnSi (CMS)
Half-metallic energy gap : 400 – 600 meV
Highly ordered L21-structure is
easily obtained.
High Tc (~ 985K)
ホイスラー TMR の発展
îF!¿0TMR-MgO-TMR
CoFeB/MgO
fâã�-TMR
ghÓç56+*âãi�RA�-!âãª�L�MR ratio�*fg!
fâã�!jkTMR*lm!!"#tuäL*lm!
�Gïk�!
90˼ÀR!îF!¿0Ø@}*~�!
TMR
CPP-GMR
!"#tun!
CCP-NOL
(Toshiba)!Heusler CPP-GMR
(Seagate)!
Heusler CPP-GMR
(HGST)!
Target
2 Tbit/in2!
3d Ferro CPP-GMR
(NHK)!3d Ferro CPP-GMR
(Toshiba)!
3d Ferro CPP-GMR
(Fujitsu)!
MR
rati
o [
%]!
RA [!·µm2]!
MgO-MTJ
Heusler CPP-GMR
(TDK)!
! The highest MR ratio (28.8%@RT) is the
best record in all of the reports to date.
Fully-epitaxial growth in CMS/Ag/CMS
Co2MnSi/Ag/Co2MnSi fully-epitaxial CPP-GMR device!
Iwase et al., Appl. Phys. Express, 2, 063003 (2009).
書き込み
読み出し
fâã7opq! 6âã7orq!
‘0’ ‘1’ 磁化反転
メモリセル配列
d�¿#^sÝ'»!¼½¾�MRAM�*tu0!
1. vVw0x1*fl!
2. �e¸¿xÛyz¢MTJÃ�*�{e!7!- âã|}~TMR*�{e!
7!- vVw0x1*�{e!
3. S12K$�*=���!7!- fx1vVw0!7!- ��)*�4!7!- CMOS˾0!
!"#tud�èé!
mRAM:nopq!
AP P
P AP
Hex: External magnetic field
Hani: Anisotropy field
P : Spin polarization factor
!: Damping parameter
": Gyromagnetic ratio
Ms: Saturation magnetization
d : Layer thickness
!"#1!}�d�45�!"#tud�èé�!
HId�!TMR / CPP-GMR
Fully epitaxial
8�O!
HId�O!
HId�O!
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F7�!
FePt(001)
Au(001) or MgO(001)
FePt(001)
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Au(001)
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HId�*�.e!
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Current-induced domain wall motion
Spin-transfer effect
MFM observation of domain wall movement
by spin polarized current in a permalloy
nanowire without external magnetic field
(A. Yamaguchi et al., PRL 92 (2004) 077205.)
!"#1-d�^FbêK'!!
Current-induced vortex core motion
(S. Kasai et al., PRL 101 (2008) 237203.)
Time-resolved M-TXM observation of
vortex core motion driven by ac current
in a permalloy disk
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rHst!
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HId�FePt/Auó!|��á=!"#î0Räå!
Electrical detection of giant spin
Hall effect at room temperature
T. Seki et al., Nature Materials, 7 (2008) 125.
Spin Hall angle ~ 0.1
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