gate control of spin transport in multilayer graphene n.
Download
Skip this Video
Download Presentation
Gate Control of Spin Transport in Multilayer Graphene

Loading in 2 Seconds...

play fullscreen
1 / 19

Gate Control of Spin Transport in Multilayer Graphene - PowerPoint PPT Presentation


  • 118 Views
  • Uploaded on

Gate Control of Spin Transport in Multilayer Graphene. By H . Goto et al. Kun Xu. Advantages. Advantages of spin over charge: Easily manipulatable with externally applied magnetic fields Long coherence/relaxation time. GMR. Giant magnetoresistance Sandwich structure FNF

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 'Gate Control of Spin Transport in Multilayer Graphene' - dominy


Download Now 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
advantages
Advantages
  • Advantages of spin over charge:
    • Easily manipulatable with externally applied magnetic fields
    • Long coherence/relaxation time
slide3
GMR
  • Giant magnetoresistance
    • Sandwich structure
      • FNF
    • Spin valve (HDD read/write heads)
    • The 2007 Nobel Prize in physics was awarded to Albert Fert and Peter Grünberg for the discovery of GMR
disadvantages
Disadvantages
  • Existing spin devices do not amplify signals
datta das device
Datta-Das Device
  • Current modulated by the degrees of precession in electron spin introduced by the gate field
spin based quantum computer
Spin-based quantum Computer
  • Qubit – intrinsic binary units
  • Quantum entanglement
  • Single electron trapped in a quantum dot
spin transport in graphite based devices
Spin transport in graphite based devices
  • Carbon nanotubes
  • Graphene
  • Multilayer graphene (MLG)
  • Weak spin-orbit and hyperfine interaction
  • Gate control of spin conduction
device structure
Device Structure
  • MLG Exfoliated from kish graphite
  • 2.5nm thick, about 7 layers (by SEM/AFM)
  • Doped Si/SiO2 substrate
device structure1
Device Structure
  • 50nm Co electrodes 200nm/330nm
  • Separated by L=290nm
device structure2
Device Structure
  • Cr/Au nonmagnetic electrodes
  • 5nm/100nm thick
measurement
Measurement
  • Four terminal lock-in technique
  • 4.2K
  • Excitation current of 1.0 uA, 119Hz
  • Back gate bias
spin signal r s
Spin Signal: Rs
  • Rs=Rp-Rap
  • Proportional to R

when FN interfaces are opaque

  • Proportional to 1/R

when FN interfaces are transparent

spin relaxation length1
Spin relaxation length
  • MLG
  • Graphene: 1.5-2 um at room temperaure, may stay the same at low temperature