Electrons spin even without an electric charge and this motion in condensed matter constitutes spin current, which is attracting a great deal of attention for next-generation technology such as memory devices. An Osaka Metropolitan University-led research group has been able to gain further insight into this important topic in the field of spintronics.

To investigate the characteristics of spin currents, OMU Graduate School of Science Professor Katsuichi Kanemoto’s group designed a multilayer device consisting of a ferromagnetic layer and an organic semiconductor material. By adopting a doped conducting polymer with a long spin relaxation time, the team succeeded in observing the effects of spin transport and spin current generation from the non-magnetic, organic semiconductor side.

The long spin relaxation times not only make for more efficiency in spintronics, but also enable direct observation of phenomena due to spin current generation in the organic layer side. Moreover, the researchers were able to find that, contrary to a theory that has been generally accepted, the width of the ferromagnetic resonance measurements for the layer of the spin current supplier slightly narrowed in the device system using the organic semiconductor with a long spin relaxation time.

“The use of the organic semiconductor makes it possible to pursue physical properties from the non-magnetic layer side, for which there was no information until now,” explained Professor Kanemoto. “Our work can be expected to contribute to a deeper understanding of the properties of spin currents.”

The findings were published in Advanced Electronic Materials.

Funding
This work was supported in part by the JSPS Kakenhi grant (numbers 19K22172 and 21H01906). We thank Idemitsu Kosan Co. Ltd., for generously providing PANI samples used in this study.

Conflicts of interest
The authors declare no conflict of interest.

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