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Diffusion thermopower of (Ga,Mn)As/GaAs tunnel junctions
Ts Naydenova1, P Dürrenfeld, K Tavakoli
1Physikalisches Institut EP3, Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany.
Physical Review Letters
|December 21, 2011
Summary
We observed tunneling anisotropic magnetothermopower, a novel voltage response in magnetic semiconductors. This discovery impacts spintronic device operation and spin injection studies.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Semiconductor Physics
Background:
- Spintronic devices utilize electron spin for enhanced functionality.
- Understanding spin-dependent transport phenomena is crucial for advancing spintronics.
- Anisotropic effects in magnetic materials offer pathways for novel device applications.
Purpose of the Study:
- To report the observation of tunneling anisotropic magnetothermopower.
- To investigate the relationship between voltage response and the magnetic semiconductor's electronic structure.
- To explore the implications of this phenomenon for spintronic devices.
Main Methods:
- Experimental observation of a voltage response across a normal/magnetic semiconductor interface under a temperature gradient.
- Analysis of the voltage signal's dependence on the magnetization direction.
Main Results:
- Demonstrated tunneling anisotropic magnetothermopower, a voltage generated by temperature differences across magnetic semiconductor interfaces.
- The observed voltage is directly related to the energy derivative of the density of states in the magnetic material.
- A strong anisotropic response of the voltage to the magnetization direction was confirmed.
Conclusions:
- Tunneling anisotropic magnetothermopower is a significant phenomenon in magnetic semiconductors.
- This effect has direct relevance for the design and operation of semiconductor spintronic devices.
- The findings may provide new insights into interpreting previous spin injection experiments.
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