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All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics
Published on: January 19, 2018
Spin injection in n-type resonant tunneling diodes
Vanessa Orsi Gordo1, Leonilson Ks Herval, Helder Va Galeti
1Physics Department, Federal University of São Carlos, São Carlos 13,565-905, Brazil. yara@df.ufscar.br.
Nanoscale Research Letters
|October 27, 2012
Summary
We observed voltage-controlled circular polarization in GaAs/AlAs/GaAlAs resonant tunneling diodes. This efficient spin injection phenomenon is linked to charged and neutral excitons under a magnetic field.
Area of Science:
- Semiconductor Physics
- Quantum Optics
- Materials Science
Background:
- Resonant tunneling diodes (RTDs) are crucial for high-frequency electronic devices.
- Understanding spin dynamics in quantum wells is key for spintronics.
- Polarized photoluminescence is a powerful tool for probing electronic states.
Purpose of the Study:
- Investigate spin injection efficiency in n-type GaAs/AlAs/GaAlAs RTDs.
- Analyze polarized photoluminescence under parallel magnetic fields.
- Characterize excitonic emission and its polarization dependence.
Main Methods:
- Utilized polarized resolved photoluminescence spectroscopy.
- Applied magnetic fields parallel to the tunnel current.
- Studied n-type GaAs/AlAs/GaAlAs resonant tunneling diodes.
Main Results:
- Observed two emission lines attributed to neutral (X) and negatively charged excitons (X-) under resonant tunneling conditions.
- Measured voltage-controlled circular polarization degree up to -88% at 15 T.
- Demonstrated efficient spin injection from 2D gases in accumulation layers.
Conclusions:
- Efficient spin injection is achievable in GaAs/AlAs/GaAlAs RTDs.
- Exciton polarization is voltage-tunable, offering control over spin states.
- This work contributes to the development of spin-based electronic devices.
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