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Shot noise induced by nonequilibrium spin accumulation.
Tomonori Arakawa1, Junichi Shiogai2, Mariusz Ciorga3
1Department of Physics, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, 560-0043 Osaka, Japan.
Physical Review Letters
|January 24, 2015
Summary
Researchers observed excess shot noise linked to spin current in a semiconductor device. This finding reveals a new method for studying spin transport and electron behavior.
Area of Science:
- Condensed matter physics
- Spintronics
- Semiconductor devices
Background:
- Shot noise arises from the discrete nature of electrons crossing potential barriers.
- Spin current involves the flow of electron spin, distinct from charge current.
- Lateral spin-valve devices enable manipulation and detection of spin currents.
Purpose of the Study:
- To investigate excess shot noise associated with spin currents.
- To explore the relationship between excess shot noise and spin current magnitude.
- To quantitatively determine spin-injection-induced electron temperature.
Main Methods:
- Utilizing an all-semiconductor lateral spin-valve device.
- Inducing nonequilibrium spin accumulation to generate spin current.
- Measuring current noise to detect excess shot noise and electron temperature.
Main Results:
- Observed excess shot noise directly correlated with the induced spin current.
- Demonstrated that excess shot noise is proportional to the spin current.
- Quantitatively determined the electron temperature influenced by spin injection.
Conclusions:
- Excess shot noise is a measurable phenomenon linked to spin currents.
- Spin accumulation driven shot noise offers a novel approach for studying nonequilibrium spin transport.
- This technique provides insights into spin dynamics in semiconductor devices.
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