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Updated: Jun 11, 2026
09:56
High Resolution Physical Characterization of Single Metallic Nanoparticles
Published on: June 28, 2019
Long spin-relaxation time in a single metal nanoparticle
Pham Nam Hai1, Shinobu Ohya, Masaaki Tanaka
1Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Nature Nanotechnology
|July 6, 2010
Summary
Researchers achieved a record spin-relaxation time of 10 microseconds in single MnAs nanoparticles. This breakthrough in metallic nanoparticles could significantly advance nanoscale spintronic devices.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Quantum Mechanics
Background:
- Spin-relaxation time is crucial for spintronic device performance.
- Semiconductor spin-relaxation times are typically ~100 ns, while bulk metals are ~ps due to scattering.
- Metallic nanoparticles can enhance spin-relaxation times via quantum size effects, reaching ~150 ns.
Purpose of the Study:
- To investigate and achieve significantly enhanced spin-relaxation times in metallic nanoparticles.
- To explore the potential of single ferromagnetic-metal nanoparticles embedded in semiconductor matrices for spintronics.
Main Methods:
- Fabrication of epitaxially grown single-crystal devices with abrupt interfaces.
- Embedding a single ferromagnetic-metal MnAs nanoparticle within a GaAs semiconductor matrix.
- Measurement of spin-relaxation time at cryogenic temperatures (2 K).
Main Results:
- Achieved a spin-relaxation time of 10 microseconds for electrons in a single MnAs nanoparticle at 2 K.
- This represents a seven-orders-of-magnitude improvement over conventional metallic systems.
- The longest spin-relaxation time reported to date for metallic nanoparticles.
Conclusions:
- Epitaxial growth and avoidance of surface contamination are key to achieving ultra-long spin-relaxation times.
- Single ferromagnetic-metal nanoparticles offer a promising platform for next-generation nanoscale spintronic devices.
- The demonstrated spin-relaxation time paves the way for advanced spintronic applications.
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