Presentation Information
[24p-1BL-2]Chirality-Induced Spin Selectivity (CISS) and Spintronics
〇Hiroshi Yamamoto1,2 (1.Inst. Mol. Sci., 2.SOKENDAI)
Keywords:
Spintronics,Chirality
In recent years, there has been a growing attempt to develop new spintronics using spin-orbit interactions in systems with broken inversion symmetry. Among these, in systems with broken top-bottom inversion symmetry, Rashba-type spin polarization, where the direction of electron motion and spin are perpendicular, is well-known. On the other hand, in chiral systems with broken left-right symmetry, a hedgehog-type spin polarization, where the electron spin and direction of motion are parallel or antiparallel, is expected to occur.The Chirality-Induced Spin Selectivity (CISS) effect, discovered at interfaces using chiral molecules, is a phenomenon of spin polarization of electrons passing through chiral molecules, fulfilling the symmetry of spin polarization as mentioned above, and is of interest as a guiding principle for new spintronics [1,2]. A characteristic of the CISS effect is the magnitude of the spin polarization, with spin polarization ratios observed that cannot be fully explained by the usual spin-orbit interaction of atoms. We have been conducting research with the view that deploying the high spin polarization rates observed in the CISS effect in solid-state devices could lead to the development of new, highly efficient spintronic devices [3-5]. As a result, it has become clear that even in solid-state systems, high spin polarization unique to chiral systems can indeed be observed in metallic or superconducting states. Furthermore, the CISS effect suggests the occurrence of spin flow-to-spin accumulation conversion, and we are also advancing our considerations on its relation to time-reversal symmetry [6].