Resolving the Ground State of the New Triangular Lattice Compound TmZn2GaO5

Triangular lattice compounds have long drawn attention due to their inherent geometric frustration and potential to host exotic phases, such as the quantum spin liquid state. Recently, the rare-earth triangular lattice compound TmMgGaO₄ has been proposed as a candidate for a spin liquid and for hosting a Kosterlitz–Thouless transition. Building on this, we successfully synthesized the related compound TmZn₂GaO₅, which adopts a distinct crystal structure that minimizes the site mixing observed in TmMgGaO₄. In earlier studies, we found no evidence of magnetic order in TmZn₂GaO₅ down to 50 mK in magnetic or thermal measurements. Here, we present additional low-temperature magnetic and inelastic neutron scattering data to further investigate the ground state of TmZn₂GaO₅, alongside mean-field theory calculations that accurately replicate the experimental findings.