Spectral densities are computed in unprecedented detail for quantum antiferromagnetic spin 1/2 two-leg ladders. These results were obtained due to a major methodical advance achieved by optimally chosen unitary transformations. The approach is based on dressed integer excitations. Considerable weight is found at high energies in the two-particle sector. Precursors of fractional spinon physics occur implying that there is no necessity to resort to fractional excitations in order to describe features at higher energies.
@article{arxiv.cond-mat/0106077,
title = {Fractional and Integer Excitations in Quantum Antiferromagnetic Spin 1/2 Ladders},
author = {C. Knetter and K. P. Schmidt and M. Grüninger and G. S. Uhrig},
journal= {arXiv preprint arXiv:cond-mat/0106077},
year = {2009}
}
Comments
6 pages, 4 figures included, minor text changes, improved figures