Abstract
The numerical simulation of quantum mechanical many-body systems by Monte Carlo Methods is in general only able to deliver ground-state or thermodynamical expectation values of physical observables. Recent developments however, made possible to perform an analytic continuation of imaginary-time quantum Monte Carlo data into real-frequency spectra. In particular the maximum-entropy method (MEM) was successfully applied to the Anderson impurity model and the Heisenberg quantum anti-ferromagnet both in one (1-D) and two (2-D) dimensions. We present here an application of the MEM on quantum Monte Carlo (QMC) simulations of the 1-D Hubbard model for large system sizes (N ≤ 84), such that the characterization of dispersion relations for excitation spectra becomes possible. The one-particle excitations posses cosine-like bands that, surprisingly, agree extremely well with slave-boson mean-field ones. Further comparisons with exact results from Bethe-Ansatz and conformai field-theory demonstrate the reliability of both the QMC simulations as well as the MEM.KeywordsHubbard ModelSpectral WeightExact DiagonalizationLuttinger LiquidQuantum Monte CarloThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
Published Version
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