We perform determinant quantum Monte Carlo simulations of the half-filled Hubbard model on a diagonally compressed kagome lattice, introducing exponential decay long-range hopping $t\left(r\right)=t_{0}exp\left(-r/r_0\right)$ to account for the evolving bond length. By varying the lattice angle $\theta$ and the on-site interaction $U$, double occupancy, charge compressibility, and spin-spin correlation functions of the whole system and each sublattice are measured. We find that geometric compression induces a clear sublattice differentiation: For $\theta \gtrsim {52}^{\circ }$, the $A$ sublattice establishes long-range hoppings, which in turn suppresses the metallic behavior of the $B/C$ sublattice and drives a selective Mott transition; for $\theta \lesssim {52}^{\circ }$, the $B-C$ chains develop long-range antiferromagnetic correlations within the finite-size simulations, which in turn suppresses the metallic behavior of the $A$ sublattice and drives a selective Mott transition. The critical interaction $U_A^c$ for the $A$ sites decreases sharply near the onset of $B-C$ antiferromagnetic correlations, while $U_{B/C}^c$ increases. These competing orders give rise to an orbital-selective Mott phase and a rich $U-\theta$ phase diagram featuring paramagnetic-metal, paramagnetic-Mott, antiferromagnetic-metal, and antiferromagnetic-Mott states. Our results highlight the complex interplay between lattice geometry, magnetic frustration, and strong correlations in frustrated two-dimensional systems.

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• Magnetic phase transitions
• Metal-insulator transition
• Kagome lattice
• Extended Hubbard model
• Hubbard model
• Quantum Monte Carlo