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In recent years, spin polarization has been observed in helical polymers despite the absence of magnetism, attracting significant attention. This phenomenon is known as chirality-induced spin selectivity (CISS). Although CISS is believed to originate from lack of inversion symmetry in materials, its microscopic mechanism remains poorly understood.

In this presentation, after reviewing the current theoretical and experimental status of CISS, we discuss the magneto-rotational effect, which describes the conversion of angular momentum between electron spins and rigid-body rotations. We then present a mechanism for the conversion between phonons and electron spins at a normal metal/chiral insulator junction [1]. If time permits, we will also briefly discuss calculations based on a one-dimensional polymer model [2].

[1] T. Funato, M. Matsuo, and T. Kato, Phys. Rev. Lett. 132, 236201 (2024)
[2] R. Sano and T. Kato, arXiv:2404.19000

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