1. The route from fundamental science to technological innovation
San Sebastian, November 27, 2017
The route from fundamental science
to technological innovation
(and the wonders of doing research)
A few examples of routes from science
to innovations in the Technologies
of Information and Communication

2. the route from fundamental research
First example:
the route from fundamental research
on electrical conduction in magnetic metals
to the “big data” stored today on hard disks
(and the birth of spin electronics)
Second example:
from quantum physics
to low power computers and telephones

3. GMR sensor (magnetic multilayer)
GMR hard disc drive
(GMR = Giant Magnetoresistance) I
GMR sensor (magnetic multilayer)
Mag. Cu

4. Opposite magnetizations:
GMR hard disc drive
(GMR = Giant Magnetoresistance) I
GMR sensor (magnetic multilayer)
Mag. Cu
Opposite magnetizations:
large resistance

5. Parallel magnetizations:
GMR hard disc drive
(GMR = Giant Magnetoresistance) I
GMR sensor (magnetic multilayer)
Mag. Cu
Parallel magnetizations:
small resistance

6. Spin dependent conduction in ferromagnetic metals
South pole
North pole
Spin up electron
Spin down electron
Electron  I
spin
charge
Ferromagnetic material (Iron, etc)

7. Spin dependent conduction in ferromagnetic metals
South pole
North pole
Spin up electron
Spin down electron
Electron  I
spin
charge
  0.3
  20
Ti V Cr Mn Fe Co Ni  
=  / 
,  ( cm) 10 20
Ferromagnetic material (Iron, etc)

8. Spin dependent conduction in ferromagnetic metals
South pole
North pole
Spin up electron
Spin down electron
Electron  I
with Co imp.
X X X X
spin
charge
  0.3
  20
Ti V Cr Mn Fe Co Ni  
=  / 
,  ( cm) 10 20
Ferromagnetic material (Iron, etc)

9. Spin dependent conduction in ferromagnetic metals
South pole
North pole
Spin up electron
Electron
with Cr imp.  I
spin
X X X X
charge
Spin down electron
  0.3
  20
Ti V Cr Mn Fe Co Ni  
=  / 
,  ( cm) 10 20
Ferromagnetic material (Iron, etc)

10. Concept of the giant magnetoresistance (GMR) I
X X X X

11. Concept of the giant magnetoresistance (GMR)
Electrons strongly slowed down in both channels: large resist.  I
X X X X
with Co and Cr imp.
X X X X
Cu layer
2 magnetic layers with antiparallel magnetizations (AP)  large resistance

12. Concept of the giant magnetoresistance (GMR)
Electrons strongly slowed down in both channels: large resist.
Short circuit by electrons in spin up channel: small resist.  I  I
XXXXXXX
X X X X
with Co and Cr imp.
with Co and Fe imp.
X X X X
Cu layer
Cu layer
Polarizer/Analyzer analogy
2 magnetic layers with antiparallel magnetizations (AP)  large resistance
2 magnetic layers with parallel magnetizations (P)  small resistance

13. Concept of the giant magnetoresistance (GMR)
Electrons strongly slowed down in both channels: large resist.
Short circuit by electrons in spin up channel: small resist.  I  I
XXXXXXX
X X X X
with Co and Cr imp.
with Co and Fe imp.
X X X X
Cu layer
Cu layer
Polarizer/Analyzer analogy
Current Perpendicular to Plane Plane-GMR
V=RI
Current in Plane-GMR

14. Molecular Beam Epitaxy (growth of metallic multilayers)

15. (Orsay, 1988, Fe/Cr multilayers, Jülich, 1989, Fe/Cr/Fe trilayers)
Giant Magnetoresistance (GMR)
(Orsay, 1988, Fe/Cr multilayers, Jülich, 1989, Fe/Cr/Fe trilayers)
Jülich
Orsay
Resistance ratio
~ + 80%
Magnetic field (kGauss)
Magnetic field (kGauss)

16. before GMR (< 1997) : 1 Gbit/in2 , today with GMR : ~ 1000 Gbit/in2
Magnetic multilayers, magnetic tunnel junctions in the read heads of hard disks of today and perspective for tomorrow I
GMR sensor,
introduced in 1997
before GMR (< 1997) : 1 Gbit/in2 ,
today with GMR : ~ 1000 Gbit/in2
Mag.
Mag. Cu

17. Extension de la technologie disque dur à l’électronique nomade
100 GB hard disc (Toshiba),
iPod
Classic: 160 G

18. Giant Magnetoresistance (1988)
Pure physics: spin and conduction
Nanotechnologies
Giant Magnetoresistance (1988)
Applications:
hard disks, sensors
medical technologies
Development of spintronics
(= electronics exploiting the spin)

19. Giant Magnetoresistance (1988)
Pure physics: spin and conduction
Nanotechnologies
Giant Magnetoresistance (1988)
Applications:
hard disks, sensors
medical technologies
Development of spintronics
(= electronics exploiting the spin)
2d example of route between science and innovation: from quantum tunneling to M-RAM

20. Hard disk and random access memory in computers
Random Access Memory (RAM)
Massive memory but low speed (ms)
High speed (nanosecond range) but « volatile » (electrical power needed to maintain memory alive)

21. After GMR, TMR (Tunnel magnetoresistance) of tunnel junctions
current
Electron « tunneling » through an insulationg « barrier » (Al2O3)
High resistance
Low resistance
RAntiparalelP > RParallel
M-RAM
Non-volatile RAM:no energy needed to keep memory alive (low consumption)

23. Today: STT-RAM (magnetic tunnel junction+ writing by Spin Transfer Torque)
Memory cell = magnetic tunnel junction
and reading by tunnel magnetoresistance
Purely electronic writing by a spin polarized current (Spin Tranfer Torque mechanism) +
High resistance
Low resistance
STT-RAM = low power RAM reducing energy comsumption in computers and telephones
Next year (2018)
in your phone
In a couple of years as embedded RAMs in the microprocessors of computers

24. Skyrmions: spin nano-balls and new track for ICTechnologies
New routes of today
Skyrmions: spin nano-balls and new track for ICTechnologies
Diameter 4 nm

25. Skyrmions: spin nano-balls and new track for ICTechnologies
New routes of today
Skyrmions: spin nano-balls and new track for ICTechnologies
Diameter 4 nm
Read
write

26. New routes of today
Solid state nanocomponents to mimic neurones and synapses in neuro-inspired computers

27. I thank you for your attention