Abstract
We study the charge dynamic structure factor of the one-dimensional Hubbard model with finite on-site repulsion at half-filling. Numerical results from the time-dependent density matrix renormalization group are analyzed by comparison with the exact spectrum of the model. The evolution of the line shape as a function of is explained in terms of a relative transfer of spectral weight between the two-holon continuum that dominates in the limit and a subset of the two-holon-two-spinon continuum that reconstructs the electron-hole continuum in the limit . Power-law singularities along boundary lines of the spectrum are described by effective impurity models that are explicitly invariant under spin and -spin rotations. The Mott-Hubbard metal-insulator transition is reflected in a discontinuous change of the exponents of edge singularities at . The sharp feature observed in the spectrum for momenta near the zone boundary is attributed to a van Hove singularity that persists as a consequence of integrability.
6 More- Received 8 November 2011
DOI:https://doi.org/10.1103/PhysRevB.85.165132
©2012 American Physical Society