Nonlinear Transverse Conductivity in Antiferroic Types of Magnetic Toroidal Metal
Phys. Rev. Lett. 135, 076502 – Published 15 August, 2025
DOI: https://doi.org/10.1103/gfl2-bsjk
Abstract
We have performed careful measurements of nonlinear transverse conductivity (NLTC) at zero field in the intermetallic compound HoAgGe with two distinct magnetic toroidal (MT) structures. Below 7 K (MT1 phase), the NLTC signal becomes observable and significantly increases with decreasing temperature, whereas between 7 and 11.6 K (MT2 phase), it remains nearly zero. However, this result is incompatible with the previous research, which assigned the former and latter MT phases as antiferro- and ferro-MT structures, respectively. This discrepancy stems from an inappropriate assignment of MT structures in prior studies. Our analysis, based on multipole theory, redefines the MT1 and MT2 phases as ferri- and antiferro-MT structures, respectively, providing a coherent framework to explain the observed NLTC in HoAgGe. These findings not only establish NLTC as a robust diagnostic tool for identifying MT metals but also highlight its potential for exploring phenomena driven by the antiferroic interactions of MT dipoles.
