Extended Metal-Insulator Crossover with Strong Antiferromagnetic Spin Correlation in Half-Filled 3D Hubbard Model

Physical Review Letters, Journal Year: 2025, Volume and Issue: 134(1)

Published: Jan. 10, 2025

The Hubbard model at temperatures above the Néel transition, despite being a paramagnet, can exhibit rich physics due to interplay of Fermi surface, on-site interaction U and thermal fluctuations. Nevertheless, understanding crossover remains only qualitative level, because intrinsically smooth behavior. Employing an improved variant numerically exact auxiliary-field quantum Monte Carlo algorithm equipped with numerical analytic continuation, we obtain broad variety thermodynamic dynamical properties three-dimensional half filling, quantitatively determine boundaries, observe that metal-insulator regime, in which antiferromagnetic spin correlations appear strongest, exists over extended regime between liquid for small Mott insulator large U. In particular, location most rapid suppression double occupancy as increases, is found fully reside metallic contrast conventional intuition it representative feature entering insulator. Beside providing reliable methodology study physics, our work also serve timely important guideline recent optical lattice experiments.

Language: Английский

Two-particle self-consistent approach for broken symmetry phases

SciPost Physics, Journal Year: 2025, Volume and Issue: 18(3)

Published: March 3, 2025

Spontaneous symmetry breaking of interacting fermion systems constitutes a major challenge for many-body theory due to the proliferation new independent scattering channels once absent or degenerate in symmetric phase. One example is given by ferro/antiferromagnetic broken phase (BSP) Hubbard model, where vertices spin-transverse and spin-longitudinal become with consequent increase computational power their calculation. We generalise non-perturbative Two-Particle-Self-Consistent method (TPSC) address SU(2) magnetic phases offering an efficient approach that incorporates strong correlations. show BSP, sum-rule enforcement susceptibilities must be accompanied modified gap equation resulting renormalisation order parameter, vertex corrections preservation gap-less feature Goldstone modes. then apply antiferromagnetic model cubic lattice at half-filling. compare our results double occupancies staggered magnetisation ones obtained using Diagrammatic Monte Carlo showing excellent quantitative agreement. demonstrate how play central role lowering Higgs resonance respect quasi-particle excitation susceptibility, yielding well visible Higgs-mode.

Language: Английский

Ising phase transitions and thermodynamics of correlated fermions in a two-dimensional spin-dependent lattice potential

Physical review. B./Physical review. B, Journal Year: 2025, Volume and Issue: 111(12)

Published: March 4, 2025

Language: Английский