We study the charge dynamic structure factor of the one-dimensional Hubbard model with finite on-site repulsion U 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 U is explained in terms of a relative transfer of spectral weight between the two-holon continuum that dominates in the limit U→ and a subset of the two-holon-two-spinon continuum that reconstructs the electron-hole continuum in the limit U→0. Power-law singularities along boundary lines of the spectrum are described by effective impurity models that are explicitly invariant under spin and η-spin SU(2) rotations. The Mott-Hubbard metal-insulator transition is reflected in a discontinuous change of the exponents of edge singularities at U=0. 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.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - Apr 20 2012|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics