Helimagnets, characterized by a helical arrangement of magnetic moments, possess unique internal degrees of freedom, including the spin phase, defined by the phase of the helical magnetic structure. Electrical detection of the spin phase is essential for both practical applications and fundamental research in helimagnets. Here, we demonstrate the electrical detection of the spin phase in a van der Waals nanoscale chiral helimagnet CrNb3S6 using nonlocal spin valve measurements. Due to the short spin diffusion length in CrNb3S6 (∼5~nm), the surface magnetic moment direction, which corresponds to the spin phase, can be detected via spin currents. The experimentally observed magnetic field dependence of the nonlocal spin valve signal is consistent with that of the surface magnetic moment in the helical magnetic structure, as supported by micromagnetic simulations. Our results establish spin currents as a powerful tool for detecting the spin phase in helimagnets, opening avenues for utilizing the spin phase as a novel internal degree of freedom in nanoscale spintronic devices.
@article{arxiv.2505.09290,
title = {Spin phase detection by spin current in a chiral helimagnet},
author = {Nan Jiang and Shota Suzuki and Issei Sasaki and Kazuki Yamada and Ryoma Kawahara and Shintaro Takada and Yusuke Shimamoto and Hiroki Shoji and Yusuke Kousaka and Jun-ichiro Ohe and Yoshihiko Togawa and Yasuhiro Niimi},
journal= {arXiv preprint arXiv:2505.09290},
year = {2025}
}