The Mott insulator - 10th order perturbation theory extended to infinite order using QMC

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We present a new method, based on the combination of analytical and numerical techniques within the framework of the dynamical mean-field theory (DMFT). Building upon numerically exact results obtained in an improved quantum Monte Carlo (QMC) scheme, 10th order strong-coupling perturbation theory for the Hubbard model on the Bethe lattice is extrapolated to infinite order. We obtain continuous estimates of energy E and double occupancy D with unprecedented precision O(10⁻⁵) for the Mott insulator above its stability edge Uc₁=4.78 as well as critical exponents. The relevance for recent experiments on Cr-doped V₂O₃ is pointed out.