Magnetic correlations in the triangular antiferromagnet FeGa2S4

Abstract

The crystal structure and magnetic correlations in triangular antiferromagnet FeGa 2 S 4 are studied by x-ray diffraction, magnetic susceptibility, neutron diffraction, and neutron inelastic scattering. We report significant mixing at the cation sites and disentangle magnetic properties dominated by major and minor magnetic sites. The magnetic short-range correlations at 0.77 Å −1 correspond to the major sites and being static at base temperature they evolve into dynamic correlations around 30-50 K. The minor sites contribute to the magnetic peak at 0.6 Å −1 , which vanishes at 5.5 K. Our analytical studies of triangular lattice models with bilinear and biquadratic terms provide the ratios between exchanges for the proposed ordering vectors. The modeling of the inelastic neutron spectrum within linear spin-wave theory results in the set of exchange couplings

Mott transition, Widom line and pseudogap in the half-filled triangular lattice Hubbard model

“…In this paper, we study the normal-state phase diagram of the Hubbard model on the triangular lattice at halffilling. This model is appropriate for several experimental systems including organic conductors with κ-ET structure [22,24,[47][48][49][50][51][52][53][54][55], some transition metal oxides [56][57][58] or sulfides [59], cobaltates [60] and artificial platforms like one-third monolayer of Sn atoms on a Si (111) surface [61], optical lattices [62] and Moiré materials like twisted-bilayer graphene and transition-metal dichalco-genides [63][64][65][66][67][68].…”