Intricately Entangled Spin and Charge Diffusion and the Coherence-Incoherence Crossover in the High-Dimensional Hubbard Model

Motivated by recent experimental studies thatinvestigate the evolution of dynamical spin and charge responses, we analyze the spin and chargediffusion spectra in both half-filled and doped one-band Hubbard model using Dynamical MeanField Theory (DMFT) combined with the Numerical Renormalization Group (NRG). We comparethe relative strengths and limitations of Density Matrix NRG (DMNRG) and Full Density MatrixNRG (FDM-NRG) in capturing low-frequency spectral features and their evolution with tempera-ture, interaction strength and band-filling.