slide1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Spintronics: How spin can act on charge carriers and vice versa PowerPoint Presentation
Download Presentation
Spintronics: How spin can act on charge carriers and vice versa

Loading in 2 Seconds...

play fullscreen
1 / 26

Spintronics: How spin can act on charge carriers and vice versa - PowerPoint PPT Presentation


  • 120 Views
  • Uploaded on

Spintronics: How spin can act on charge carriers and vice versa. Tom as Jungwirth. University of Nottingham. Institute of Physics Prague. . Mott with spin current . Mott with out spin current . ‪ Spintronics ‬ From Wikipedia, the free encyclopedia

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Spintronics: How spin can act on charge carriers and vice versa' - una


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

Spintronics: How spin can act on charge carriers and vice versa

TomasJungwirth

Universityof Nottingham

Institute of Physics Prague

slide2

Mott with spin current

Mott withoutspin current

‪Spintronics

‬From Wikipedia, the free encyclopedia

Spintronics (a pormanteau meaning

spin transport electronics)....

I

I

GMR

1988

MRAM

2006

Dirac withoutcurrent through magnet

Dirac with current through magnet

I

AMR

1857

HD Read-heads

1990‘s

I

I

I

slide3

Mott with ferromagnets

Mott with antiferromagnets

I

I

I

I

Dirac with ferromagnets

Dirac with antiferromagnets

I

I

I

I

slide4

Control by current

via spin torques:

scales with current density

0.1 pJ

Control by photo-carriers

via spin torques:

sub ps timescales

Magnetic-field control of FMs:

scales with current

Laser

Relativistic spin-orbit torques might work equally well in AFMs plus photocarriers in SCs

Electro-static field control via relativistic

magnetic anisotropy effects:

1fJ

Should work equally well or better

in AFMs: more choices including SCs

(or piezo-electric)

slide5

Writing by current

via spin torques:

scales with current density

0.1 pJ

Writing by photo-carriers

via spin torques:

sub ps timescales

Laser

Relativistic spin-orbit torques might work equally well in AFMs plus photocarriers in SCs

slide6

Optical spin-transfer torque

OSTT

s

Pn

Pn

M

M

s

M

M

Němec, Tesařová, Novák, TJ et al. Nature Phys.’12, Nature Photonics ‘13, Nature Commun. ‘13

Fernandez-Rossier, Nunez, Abofath, MacDonald cont-mat/0304492

slide7

Optical spin-transfer torque

OSTT

s

Pn

Pn

M

M

s

Němec, Tesařová, Novák, TJ et al. Nature Phys.’12, Nature Photonics ‘13, Nature Commun. ‘13

Fernandez-Rossier, Nunez, Abofath, MacDonald cont-mat/0304492

slide8

Optical spin-transfer torque

OSTT

s

Pn

Pn

M

M

s

Němec, Tesařová, Novák, TJ et al. Nature Phys.’12, Nature Photonics ‘13, Nature Commun. ‘13

Fernandez-Rossier, Nunez, Abofath, MacDonald cont-mat/0304492

slide9

Electrical spin-transfer torque

Antidamping-like (adiabatic) STT

OSTT

Pn

M

s

Zhang and Li PRL 2004

Vanhaverbeke et al. PRB 2007,......

slide10

Electrical spin-transfer torque

Field-like (non-adiabatic) STT

s

Pn

M

Zhang and Li PRL 2004

Vanhaverbeke et al. PRB 2007,......

slide11

Electrical spin-transfer torque

Antidamping-like STT

Field-like STT

~

small  in weakly SO-coupled dense-momentmetal FMs

large  in strongly SO-coupled dilute-moment (Ga,Mn)As

slide13

Electrical spin-transfer torque: current induced DW motion

vDW

 = 0

“intrinsic” pinning

j

jC

Antidamping STT

Antidamping-like STT

Zhang & Li, PRL 93, 127204 (2004)

Vanhaverbeke & Viret, PRB 75, 024411 (2007)

slide14

Electrical spin-transfer torque: current induced DW motion

vDW

 < 

j

jC

Antidamping STT

Antidamping-like STT

Zhang & Li, PRL 93, 127204 (2004)

Vanhaverbeke & Viret, PRB 75, 024411 (2007)

Field-like STT

slide15

Electrical spin-transfer torque: current induced DW motion

vDW

 > 

 < 

j

jC

jC

Antidamping STT

Antidamping-like STT

Zhang & Li, PRL 93, 127204 (2004)

Vanhaverbeke & Viret, PRB 75, 024411 (2007)

Field-like STT

slide16

Steady-state carrier spin polarization  torque

QM averaging in non-equilibrium

Electrical spin injection

Non-relativistic STT

Steady state

Optical spin injection

External

OSTT

antidamping-like torque

M

slide17

Steady-state carrier spin polarization  torque

QM averaging in non-equilibrium

Electrical spin injection

Relativistic SOT

Internal

Steady state

Optical spin injection

(Ga,Mn)As

OSOT

M

slide18

Steady-state carrier spin polarization  torque

Linear response: eigenstates of H

& non-equilibrium distribution

Electrical drift and relaxation:

broken inversion symmetry

Relativistic SOT

Internal

Steady state

Optical generation and relaxation

slide19

Paramagnets

Spin-orbit

Magnetic field of moving nucleus

in electron‘srest frame

Spin-galvanic effect

= SOT without acting on

Electrical drift and relaxation:

broken inversion symmetry

Aronov, Lyanda-Geller, JETP ’89, Edelstein SSC ’90, Ganichev et al. Nature ‘02

slide20

Paramagnets

Spin-orbit

Magnetic field of moving nucleus

in electron‘srest frame

Spin Hall effect

slide21

MRAM switching by in-plane current  SHE spin-current  non-relativistic STT

Ralph, Buhrman,et al., Science ‘12

Hall antidamping STT

SHE in Pt acts as the external polarizer

slide22

MRAM switching by in-plane current  attractive alternative to perp. current STT

Conventional perpendicular current STT

slide23

MRAM switching by in-plane current  attractive alternative to perp. current STT

Conventional perpendicular current STT

slide24

Competing scenario: In-plane current swithing by relativitic SOT due to broken structural inversion symmetry at Co/Pt?

Miron et al., Nature ‘11

slide25

Ralph, Buhrman et al.: SHE

Miron et al.: SOT

-We see antidamping-like torque

-SOT is field-like so we exclude it

- non-relativistic STT in metals is

dominated by the antidamping torque

-We also see antidamping-like torque

-SOT is field-like but maybe there is some

antidamping-like SOT as well