Osaka Prefecture University

Chiral crystals blowing off polarized spins: Phenomena detected without magnets !

LastUpDate: June 17, 2020

Chiral crystals blowing off polarized spins: Phenomena detected without magnets !

Schematics of crystalline structures of chiral crystals CrNb3S6 and spin-polarization phenomena in chiral materials. A tiny helical structure at atomic scale generates spin-polarized current (electron flow).

The researchers, Prof. Yoshihiko Togawa at Osaka Prefecture University (President : Masahiro Tatsumisago), Prof. Hiroshi Yamamoto at Institute for Molecular Science (Director General : Maki Kawai), Prof. Jun-ichiro Kishine at The Open University of Japan (President : Shin Kisugi), and Prof. Jun-ichiro Ohe, at Toho University (President : Ken Takamatsu)  have discovered that a chiral crystal, which exhibits no magnetism, works as a polarizer of electron spins when the charge current is applied at room temperature in the absence of magnetic field.

This phenomenon is likely to be originated from the nature that the crystal has a chiral structure. The present work makes a fundamental contribution in revealing universal properties that a wide variety of chiral materials should exhibit.

This result was published in “Physical Review Letters”, the American Physical Society’s flagship publication,  on April 21, 2020.

Journal Title: “Chirality-Induced Spin-Polarized State of a Chiral Crystal CrNb3S6
Press Release (Japanese text)(322KB)

Short summary

This study reports the following findings for the first time.

  • A chiral crystal, which exhibits no magnetism at room temperature, generates a spin polarized current.
  • A spin-polarized state is detected electrically in a solid crystal without using magnets or magnetic fields.
  • A spin-polarized state generated electrically in the chiral crystal retains robutstly over the whole crystal.
  • A handedness of chiral crystal structures is distinguishable by using this phenomenon.
  • Spin-polarized phenomena occur universally in a wide range of chiral materials including chiral crystals.

Financial Supports

Grants-in-Aid for Scientific Research, Research Grant of Specially Promoted Research (No. 17H02767, No. 17H02923, No. 19K03751, and No. 19H00891.)
Specially Promoted Research Program by Toyota Physical and Chemical Research Institute (Toyota RIKEN)

Contact:

Department of Physics and Electronics, Osaka Prefecture University,
Dr. Yoshihiko Togawa (Professor)

Tel 072-254-8216
E-mail  y-togawa[at]pe.osakafu-u.ac.jp
*Please change [at] to @.