Fig. 3: Fidelity susceptibility and order parameters of the J1-J2-J3 Heisenberg model.
From: Foundation neural-networks quantum states as a unified Ansatz for multiple hamiltonians
a Fidelity susceptibility of the J1-J2-J3 Heisenberg model on a 10 × 10 square lattice [see Eq. (4)]. For each point of the phase diagram of the system, we visualize the direction of the leading eigenvector of the quantum geometric tensor χ(γ) [see Eq. (22)]. The colour associated to each line is related to corresponding eigenvalue clipped in the interval [0.0, 0.5] for visualization purposes. b The order parameter \({m}_{{{{\rm{N}}}}\acute{{{{\rm{e}}}}}{{{\rm{el}}}}}^{2}({{{\boldsymbol{\gamma }}}})\) characterizing the Néel antiferromagnetic order. c The order parameter \({m}_{{{{\rm{stripe}}}}}^{2}({{{\boldsymbol{\gamma }}}})\) identifying the antiferromagnetic phase with stripe order. d The order parameter d2(γ) probing the valence bond phase. In all panels, the order parameters are computed over a dense grid of \({{{\mathcal{R}}}}=4000\) uniformly distributed points in the parameter space defined by J2/J1 ∈ [0, 1.0] and J3/J1 ∈ [0, 0.6].
