Electrical switching of an unconventional odd parity magnet
Abstract
Magnetic states with zero magnetization but non-relativistic spin splitting are outstanding candidates for the next generation of spintronic devices. Their electron-volt (eV) scale spin splitting, ultrafast spin dynamics and nearly vanishing stray fields make them particularly promising for several applications. A variety of such magnetic states with nontrivial spin textures have been identified recently, including even-parity d, g, or i-wave altermagnets and odd-parity p-wave magnets. Achieving voltage-based control of the nonuniform spin polarization of these magnetic states is of great interest for realizing energyefficient and compact devices for information storage and processing. Spin-spiral type-II multiferroics are optimal candidates for such voltage-based control, as they exhibit an inversion-symmetry-breaking magnetic order which directly induces ferroelectric polarization, allowing for symmetry protected cross-control between spin chirality and polar order. Here we combine photocurrent measurements, first-principle calculations and group-theory analysis to provide direct evidence that the spin polarization of the spin-spiral type-II multiferroic NiI2 exhibits odd-parity character connected to the spiral chirality. The symmetry-protected coupling between chirality and polar order enables electrical control of a primarily non-relativistic spin polarization. Our findings represent the first direct observation of unconventional odd-parity magnetism in a spin-spiral type-II multiferroic, and open a new frontier of voltage-based switching of non-relativistic spin polarization in compensated magnets.
Cite
@article{arxiv.2504.21086,
title = {Electrical switching of an unconventional odd parity magnet},
author = {Qian Song and Srdjan Stavrić and Paolo Barone and Andrea Droghetti and Daniil S. Antonenko and Jörn W. F. Venderbos and Connor A. Occhialini and Batyr Ilyas and Emre Ergeçen and Nuh Gedik and Sang-Wook Cheong and Rafael M. Fernandes and Silvia Picozzi and Riccardo Comin},
journal= {arXiv preprint arXiv:2504.21086},
year = {2025}
}