Near itinerancy and slow singlet formation in the triangular lattice
Phys. Rev. B 114, 254407 – Published 10 November, 2026
DOI: https://doi.org/10.1103/stcm-49fx
Abstract
forms a delafossitelike structure that contains triangular sublattices of edge-sharing octahedra. It shows no evidence of magnetic order down to 100 mK and persistent spin fluctuations, suggestive of a quantum disordered magnetic ground state. In order to characterize the physical regime from which this disordered state arises, we use resonant inelastic x-ray scattering (RIXS) and x-ray absorption spectroscopy (XAS) at the edge, along with pulsed high-field magnetization to characterize both the local electronic structure and the magnetic interactions. We infer significant spin-orbit coupling from XAS measurements. With RIXS, we observe intraorbital excitations, which are damped due to the near itinerancy of the band and suggestive of strong charge fluctuations. Corroborated by fits of the high-field magnetization to a random singlet model, we propose a picture of a nearly itinerant system with strong magnetic and charge fluctuations that destabilize long-range magnetic order.
