2025/01/14 by Nanse Esaki, Esaki, Nanse, Gyungchoon Go +3
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Covalent Organic Framework Applications #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.2501.07906
openalex publication_date 2025/01/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The scalar spin chirality (SSC), defined as a triple product of spins, is essential for describing noncoplanar spin structures and understanding chiral physics in magnetic systems. Traditionally, SSC has been discussed primarily in the context of noncoplanar ground-state spin configurations at zero temperature, as collinear spin systems are generally thought to lack SSC. Consequently, whether the SSC can emerge at finite temperatures in spin systems with collinear ground states remains an open question and has yet to be fully understood. In this study, we theoretically demonstrate that thermally excited magnons can induce SSC even in collinear spin systems. By considering 2D ferromagnets on Kagome and honeycomb lattices, we demonstrate that the Dzyaloshinskii-Moriya interactions (DMI) which break the effective time-reversal symmetry in the magnon Hamiltonian can lead to finite SSC at finite temperatures. Using a simple spin model, we show both numerically and analytically that the SSC increases with the magnitude of DMI and temperature. Furthermore, calculations based on realistic material parameters reveal that the magnon-induced SSC can achieve a magnitude comparable to those observed in non-coplanar spin configurations. These findings suggest that SSC plays a significant role even in collinear spin systems, providing new insights into the chiral physics of magnetic materials.