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arXiv · 2210.17423

Symmetry-broken perturbation theory to large orders in antiferromagnetic phases

R. Garioud·F. Šimkovic IV·R. Rossi·G. Spada·T. Schäfer·F. Werner·M. Ferrero
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Abstract

We introduce a spin-symmetry-broken extension of the connected determinant algorithm [Phys. Rev. Lett. 119, 045701 (2017)]. The resulting systematic perturbative expansions around an antiferromagnetic state allow for numerically exact calculations directly inside a magnetically ordered phase. We show new precise results for the magnetic phase diagram and thermodynamics of the three-dimensional cubic Hubbard model at half-filling. With detailed computations of the order parameter in the low to intermediate-coupling regime, we establish the N{\'e}el phase boundary. The critical behavior in its vicinity is shown to be compatible with the $O(3)$ Heisenberg universality class. By determining the evolution of the entropy with decreasing temperature through the phase transition we identify the different physical regimes at $U/t\!=\!4$. We provide quantitative results for several thermodynamic quantities deep inside the antiferromagnetic dome up to large interaction strengths and investigate the crossover between the Slater and Heisenberg regimes.

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R. Garioud, F. Šimkovic IV, R. Rossi, G. Spada, T. Schäfer, F. Werner, M. Ferrero. 2022-10-31. Symmetry-broken perturbation theory to large orders in antiferromagnetic phases. https://doi.org/10.1103/physrevlett.132.246505

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