Signatures of spin and charge energy scales in the local moment and specific heat of the half-filled two-dimensional Hubbard model - art. no. 125116

Local moment formation driven by the on-site repulsion U is one of the most fundamental features in the Hubbard model. At the simplest level, the temp erature dependence of the local moment is expected to have a single structu re at T similar toU, reflecting the suppression of the double occupancy. In this paper we show low-temperature quantum Monte Carlo data for half-filli ng which emphasize that the local moment also has a signature at a lower en ergy scale which previously had been thought to characterize only the tempe ratures below which moments on different sites begin to correlate locally. We discuss implications of these results for the structure of the specific heat, and connections to quasiparticle resonance and pseudogap formation in the density of states.