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Measurement of Coherence Decay in GaMnAs Using Femtosecond Four-wave Mixing
Published on: December 3, 2013
High temperature ferromagnetism in GaAs-based heterostructures with Mn delta doping
A M Nazmul1, T Amemiya, Y Shuto
1Department of Electronic Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Physical Review Letters
|August 11, 2005
Summary
Designing magnetic semiconductor heterostructures with Mn-doped GaAs and AlGaAs layers achieved high ferromagnetic transition temperatures (T(C)) up to 250 K. This breakthrough enables advanced spintronic devices by controlling magnetic moment overlap with the hole gas.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Semiconductor Spintronics
Background:
- Magnetic semiconductor heterostructures are crucial for spintronic applications.
- Achieving high ferromagnetic transition temperatures (T(C)) in these materials remains a challenge.
- Controlling the interaction between magnetic dopants and charge carriers is key.
Purpose of the Study:
- To design and fabricate novel magnetic semiconductor heterostructures.
- To investigate methods for enhancing ferromagnetic transition temperatures (T(C)).
- To explore the anomalous Hall effect in high T(C) materials.
Main Methods:
- Fabrication of Mn delta-doped GaAs and p-type AlGaAs heterostructures.
- Optimization of growth sequences and low-temperature annealing to reduce Mn interstitials.
- Characterization of magnetic properties and anomalous Hall effect measurements.
Main Results:
- Realized high ferromagnetic transition temperatures (T(C)) up to 250 K.
- Demonstrated effective control over Mn dopant distribution and overlap with the 2D hole gas.
- Observed peculiar temperature-dependent anomalous Hall effect behavior.
Conclusions:
- Suitably designed magnetic semiconductor heterostructures can achieve significantly enhanced T(C).
- Reducing Mn interstitials through optimized growth and annealing is critical for high T(C).
- These findings pave the way for high-temperature spintronic devices.
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