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Nonthermal photocoercivity effect in a low-doped (Ga,Mn)As ferromagnetic semiconductor
G V Astakhov1, H Hoffmann, V L Korenev
1Physikalisches Institut (EP3), Universität Würzburg, 97074 Würzburg, Germany. astakhov@physik.uni-wuerzburg.de
Physical Review Letters
|June 13, 2009
Summary
Researchers observed a photocoercivity effect (PCE) in (Ga,Mn)As ferromagnetic semiconductors. Light locally alters magnetic properties, enabling erasable magnetic image writing.
Area of Science:
- Condensed matter physics
- Materials science
- Spintronics
Background:
- Ferromagnetic semiconductors offer potential for spintronic devices.
- Controlling magnetic properties with external stimuli is crucial for device applications.
Purpose of the Study:
- To investigate the photoinduced change of the coercive field in low-doped (Ga,Mn)As.
- To explore the mechanism and characteristics of the observed photocoercivity effect (PCE).
Main Methods:
- Low-intensity illumination of (Ga,Mn)As samples.
- Measurement of coercive field changes.
- Spatially resolved magnetization reversal dynamics.
- Correlation analysis with sample resistivity.
Main Results:
- A significant photocoercivity effect (PCE) was observed under low-intensity light.
- Strong correlation found between PCE and sample resistivity.
- Magnetization reversal dynamics confirmed the absence of thermal heating effects.
- Proposed mechanism: light-induced lowering of domain wall pinning energy.
Conclusions:
- The observed PCE in (Ga,Mn)As is attributed to light-induced changes in domain wall pinning.
- The effect is local and reversible, demonstrating potential for optical magnetic data storage.
- PCE offers a novel method for writing and erasing magnetic images using light.
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