2 research outputs found
Critical Properties of Spectral Functions for the 1D Anisotropic t-J Models with an Energy Gap
We exactly calculate the momentum-dependent critical exponents for spectral
functions in the one-dimensional anisotropic t-J models with a gap either in
the spin or charge excitation spectrum. Our approach is based on the Bethe
ansatz technique combined with finite-size scaling techniques in conformal
field theory. It is found that the spectral functions show a power-law
singularity, which occurs at frequencies determined by the dispersion of a
massive spin (or charge) excitation.We discuss how the nontrivial contribution
of a massive excitation controls the singular behavior in optical response
functions.Comment: 4 pages, REVTeX, 2 figures(available upon request), accepted for
publication in JPSJ 66 (1997) No.