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Terahertz spin current pulses controlled by magnetic heterostructures
T Kampfrath1, M Battiato, P Maldonado
1Department of Physical Chemistry, Fritz Haber Institute, Faradayweg 4-6, 14195 Berlin, Germany. kampfrath@fhi-berlin.mpg.de
Nature Nanotechnology
|April 2, 2013
Summary
Researchers can shape ultrafast spin current pulses using magnetic heterostructures. Tailoring materials like ruthenium or gold allows control over electron spin transport for advanced spintronic devices.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Spintronics
Background:
- Spintronics encodes information using electron spin.
- Controlled spin transport is crucial for spintronic devices.
- Terahertz frequencies offer unexplored potential for high-speed electronics.
Purpose of the Study:
- To demonstrate the manipulation of femtosecond spin current burst shapes.
- To investigate the influence of different cap layers on spin current dynamics.
- To explore the potential for engineering terahertz emitters.
Main Methods:
- Utilizing femtosecond laser pulses to generate spin currents.
- Employing magnetic heterostructures with varying cap layers (ruthenium, gold).
- Detecting transient spin currents via the inverse spin Hall effect (ISHE).
Main Results:
- Spin current pulse duration is significantly affected by the cap layer material.
- Ruthenium cap layers result in longer spin current pulses due to lower electron mobility.
- Gold cap layers exhibit shorter spin current pulses due to higher electron mobility.
Conclusions:
- Magnetic heterostructures enable the tailoring of spin current pulse shapes.
- Material selection (e.g., Ru vs. Au) controls electron spin transport and pulse duration.
- This offers a pathway for developing high-speed spintronic devices and terahertz emitters.
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