2024/12/16 by Kozlowski, Stashu, Derek Churchill, Churchill, Derek +2
Engineering · Materials Science · Physics and Astronomy · #FOS: Physical sciences #Optical and Acousto-Optic Technologies #Perovskite Materials and Applications #Solid-state spectroscopy and crystallography #Strongly Correlated Electrons (cond-mat.str-el)
paper · pdf · doi:10.48550/arxiv.2412.12280
openalex publication_date 2024/12/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Motivated by the time-reversal symmetry breaking signal in muon spin relaxation below a transition temperature without accompanying noticeable magnetic Bragg peaks in 5d2 Os double perovskites, a rare ferro-octupolar order was proposed to account for such hidden order. Here we study the phase transitions under a magnetic field in triangular and face-centered cubic lattices using classical Monte Carlo simulations. It is expected that higher-rank moments do not couple linearly to the magnetic field. Consequently, a field applied along the ferro-octupolar order is not anticipated to influence the ordering. However, we observe the emergence of antiferro-quadrupolar ordering mixed with the antiferro-octupolar order (AFQO) due to the field-induced bond-dependent exchange interaction. This field-linear interaction among non-Kramer doublets arises via the coupling to the excited triplet states enabled by the external field. In the triangular lattice, we uncover intriguing vortex states, which could inspire future research into 5d2 triangular lattice systems.