experiments to probe the inverse spin-hall effect in gaas
DESCRIPTION
DFG Meeting „Halbleiter-Spintronik“. Experiments to probe the inverse Spin-Hall Effect in GaAs U. Pfeuffer, R. Neumann, D. Schuh, W. Wegscheider, D. Weiss 7. June 2008. University of Regensburg. DFG Meeting University of Regensburg. - PowerPoint PPT PresentationTRANSCRIPT
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Experimentsto probe
the inverse Spin-Hall Effect in GaAs
U. Pfeuffer, R. Neumann, D. Schuh, W. Wegscheider, D. Weiss
7. June 2008 University of Regensburg
DFG Meeting„Halbleiter-Spintronik“
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DFG Meeting University of Regensburg
CONTENT
06/07/08 Experiments to probe the inverse Spin-Hall Effect in GaAs
Motivation
Spin-Hall Structure
Sample Preparation
Measurements
Conclusion
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DFG Meeting University of Regensburg
MOTIVATION
06/07/08 Experiments to probe the inverse Spin-Hall Effect in GaAs
Spin-Hall Effect
Electric field induces transverse spin-current due to spin-orbit scattering.
Inverser Spin-Hall Effect
Spincurrent induces a transverse charge-current.
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DFG Meeting University of Regensburg
MOTIVATION
06/07/08 Experiments to probe the inverse Spin-Hall Effect in GaAs
Spin-Hall-Structure
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DFG Meeting University of Regensburg
MOTIVATION
06/07/08 Experiments to probe the inverse Spin-Hall Effect in GaAs
Valenzuela & Trinkham Electrical measurements in diffusive metallic conductor.
Spincurrent injected out of ferromagnetic CoFe through Al2O3 tunneling barrier in Al Hall-Bar.
Spin detection without magnetic materials.
Spincurrent induces due to spin-orbit scatteringa transversve Spin-Hall imbalance → USH
External B-field defines direction of spins
AFM image, S.O. Valenzuela et al., Nature Lett. 442, 13 (2006)
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DFG Meeting University of Regensburg
MOTIVATION
06/07/08 Experiments to probe the inverse Spin-Hall Effect in GaAs
Valenzuela & Trinkham
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DFG Meeting University of Regensburg
SAMPLE PREPARATION
06/07/08 Experiments to probe the inverse Spin-Hall Effect in GaAs
Material
3.2 Preparation
- Zn pads annealing @ 500°C- Hall-Bar (acetic acid)- Au contacts- EBL- Fe sputtering + Au (80nm + 100nm)
Wafer D070313B (grown by D. Schuh, Workgroup W. Wegscheider, University of Regensburg)
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DFG Meeting University of Regensburg
MEASUREMENTS
06/07/08 Experiments to probe the inverse Spin-Hall Effect in GaAs
Sample 1 „bad sample“
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DFG Meeting University of Regensburg
MEASUREMENTS
06/07/08 Experiments to probe the inverse Spin-Hall Effect in GaAs
Sample 1 „bad sample“
![Page 10: Experiments to probe the inverse Spin-Hall Effect in GaAs](https://reader036.vdocument.in/reader036/viewer/2022062500/568157c9550346895dc552f5/html5/thumbnails/10.jpg)
DFG Meeting University of Regensburg
MEASUREMENTS
06/07/08 Experiments to probe the inverse Spin-Hall Effect in GaAs
Sample 1 „bad sample“
![Page 11: Experiments to probe the inverse Spin-Hall Effect in GaAs](https://reader036.vdocument.in/reader036/viewer/2022062500/568157c9550346895dc552f5/html5/thumbnails/11.jpg)
DFG Meeting University of Regensburg
MEASUREMENTS
06/07/08 Experiments to probe the inverse Spin-Hall Effect in GaAs
Sample 1 „bad sample“
Change of polarization of injected current ?
J. Moser et al.Appl. Phys. Lett. 89, 162106 (2006)
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DFG Meeting University of Regensburg
MEASUREMENTS
06/07/08 Experiments to probe the inverse Spin-Hall Effect in GaAs
Reproducibility
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DFG Meeting University of Regensburg
MEASUREMENTS
06/07/08 Experiments to probe the inverse Spin-Hall Effect in GaAs
Sample 2 „good sample“
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DFG Meeting University of Regensburg
MEASUREMENTS
06/07/08 Experiments to probe the inverse Spin-Hall Effect in GaAs
Sample 2 „good sample“
![Page 15: Experiments to probe the inverse Spin-Hall Effect in GaAs](https://reader036.vdocument.in/reader036/viewer/2022062500/568157c9550346895dc552f5/html5/thumbnails/15.jpg)
DFG Meeting University of Regensburg
MEASUREMENTS
06/07/08 Experiments to probe the inverse Spin-Hall Effect in GaAs
Sample 2 „good sample“
![Page 16: Experiments to probe the inverse Spin-Hall Effect in GaAs](https://reader036.vdocument.in/reader036/viewer/2022062500/568157c9550346895dc552f5/html5/thumbnails/16.jpg)
DFG Meeting University of Regensburg
CONCLUSION & OUTLOOK
06/07/08 Experiments to probe the inverse Spin-Hall Effect in GaAs
Measured signal looks like inverse „Spin-Hall-Effect“ on GaAs
Further tests
Non-ferromagnetic injector
Structure with different distances from injector
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Thank You For Your Attention
"The most exciting aspect of this finding is that you don't know exactly where it's going to lead“
D.D.AwschalomUniversity of Regensburg
DFG Meeting„Halbleiter-Spintronik“