2025/05/14 by Nanse Esaki, Esaki, Nanse, Yutaka Akagi +5 · 3 citations
Physics and Astronomy · #FOS: Physical sciences #Magnetic properties of thin films #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Strongly Correlated Electrons (cond-mat.str-el)
paper · pdf · doi:10.48550/arxiv.2505.09420
openalex publication_date 2025/05/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
We present a comprehensive theoretical study of the topological properties of triplon excitations in spin-1/2 dimer-singlet ground states defined on the maple leaf and star lattices. Our analysis is based on a model that includes Heisenberg interactions, Dzyaloshinskii-Moriya (DM) interactions, and an external magnetic field. In the absence of an in-plane DM vector, we demonstrate that the triplon Hamiltonian maps onto the magnon Hamiltonian of the Kagome lattice, inheriting its nontrivial topological characteristics, including Berry curvature and topological invariants such as the Z2 invariant and Chern numbers. This correspondence enables us to derive analytical expressions for the spin Nernst and thermal Hall conductivities at low temperatures. Furthermore, we explore the effects of realistic finite in-plane DM interactions, uncovering multiple topological transitions and a complex thermal Hall conductivity behavior, including potential sign reversals as functions of magnetic field and temperature. Using layer groups, we also provide a symmetry classification of the star and maple leaf lattices.