Nanoparticle-filled magnetic garnet film generates photoelectricity in a new way, via spintronics

Jan. 16, 2015
As noted in Tech-On!, Tohoku University (Tohoku, Japan) and Japan Atomic Energy Agency (JAEA; Saitama, Japan) have discovered that a spin current can be generated by applying light to an insulating material.

As noted in Tech-On!, researchers at Tohoku University (Tohoku, Japan) and Japan Atomic Energy Agency (JAEA; Saitama, Japan) have discovered that a spin current can be generated by applying light to an insulating material.1 They also developed surface-plasmon-resonance-based technology to convert a spin current to an electric current.

A spin current is an element of spintronics, a mostly research-stage technology that relies on the electron's spin and magnetic moment, as well as its traditionally exploited charge, to enable practical semiconductor-based devices (memory storage devices have already been developed). The use of spin current as an intermediary step between light and electrical current is a new energy-conversion principle.

As an insulating material, they used a magnetic garnet (BiY2Fe5O12) thin film embedded with gold (Au) nanoparticles with a diameter of 100 nm or less. A platinum (Pt) thin film was coated on top of the garnet film.

When light with a wavelength of about 690 nm irradiates the device, a strong localized magnetic field is generated around the Au nanoparticles due to surface-plasmon resonance, exciting spin motions. The spin current injected into the Pt film is converted within the Pt to an electromotive force due to "inverse spin-Hall effects," which are related to quantum relativity theory.

In an experiment, the university and JAEA measured the electromotive force generated by the inverse spin-Hall effects and proved that the detected signals were derived from the spin current generated from the magnetic garnet. Through a simulation, they separated the effects of heat generated by the applied light.

The latest research results will contribute to the formation of a new research field combining surface-plasmon and spin current and the research and development of electrical/magnetic devices that do not require an external power source, says Tech-on!. For example, because a spin current can be generated from heat, sound waves, and other sources, it might become possible to realize a device that can use multiple energy sources including light at the same time.

source: http://techon.nikkeibp.co.jp/english/NEWS_EN/20150115/399085/

REFERENCE:

1. Uchida K. et al., Nature Communications (2015); doi: 10.1038/ncomms6910

Sponsored Recommendations

Brain Computer Interface (BCI) electrode manufacturing

Jan. 31, 2025
Learn how an industry-leading Brain Computer Interface Electrode (BCI) manufacturer used precision laser micromachining to produce high-density neural microelectrode arrays.

Electro-Optic Sensor and System Performance Verification with Motion Systems

Jan. 31, 2025
To learn how to use motion control equipment for electro-optic sensor testing, click here to read our whitepaper!

How nanopositioning helped achieve fusion ignition

Jan. 31, 2025
In December 2022, the Lawrence Livermore National Laboratory's National Ignition Facility (NIF) achieved fusion ignition. Learn how Aerotech nanopositioning contributed to this...

Nanometer Scale Industrial Automation for Optical Device Manufacturing

Jan. 31, 2025
In optical device manufacturing, choosing automation technologies at the R&D level that are also suitable for production environments is critical to bringing new devices to market...

Voice your opinion!

To join the conversation, and become an exclusive member of Laser Focus World, create an account today!