{
  "id": "2412.10808",
  "version": "v1",
  "published": "2024-12-14T12:13:09.000Z",
  "updated": "2024-12-14T12:13:09.000Z",
  "title": "Localized fermions on the triangular lattice with Ising-like interactions",
  "authors": [
    "Lubomíra Regeciová",
    "Konrad Jerzy Kapcia"
  ],
  "comment": "11 pages, 6 figures (8 panels), 71 references; RevTeX class, double-column formatting",
  "categories": [
    "cond-mat.stat-mech",
    "cond-mat.other",
    "cond-mat.quant-gas",
    "cond-mat.str-el",
    "physics.comp-ph"
  ],
  "abstract": "The model of localized fermions on the triangular lattice is analyzed in means of the Monte Carlo simulations in the grand canonical ensemble. The Hamiltonian of the system has a form of the extended Hubbard model (at the atomic limit) with nearest-neighbor Ising-like magnetic $J$ interactions and onsite Coulomb $U$ interactions. The model is investigated for both signs of $J$, arbitrary $U$ interaction and arbitrary chemical potential $\\mu$ (or, equivalently, arbitrary particle concentration $n$). Based on the specific heat capacity and sublattice magnetization analyses, the phase diagrams of the model are determined. For ferromagnetic case ($J<0$), the transition from the ordered phase (which is a standard ferromagnet and can be stable up to $k_{B}T/|J| \\approx 0.61$) is found to be second-order (for sufficiently large temperatures $k_{B}T/|J| \\gtrsim 0.2$) or first-order (for $-1<U/|J|<-0.65$ at the half-filling, i.e., $n=1$). In the case of $J>0$, the ordered phase occurs in a range of $-1/2<U/|J|<0$ (for $n=1$), while for larger $U$ the state with short-range order is also found (also for $n \\neq 1$). The ordered phase is characterized by an antiferromagnetic arrangement of magnetic moments in two sublattices forming the hexagonal lattice. The transition from this ordered phase, which is found also for $\\mu \\neq 0$ ($n \\neq 1$) and $U/|J|>-1/2$ is always second-order for any model parameters. The ordered phase for $J>0$ can be stable up to $k_{B}T/|J| \\approx 0.06$.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2024-12-14T12:13:09.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "triangular lattice",
      "localized fermions",
      "ordered phase",
      "ising-like interactions",
      "sublattice magnetization analyses"
    ],
    "note": {
      "typesetting": "RevTeX",
      "pages": 11,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}