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Fractional and Integer Excitations in Quantum Antiferromagnetic Spin 1/2 Ladders

C. Knetter·K. P. Schmidt·M. Grüninger·G. S. Uhrig
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Abstract

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.

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C. Knetter, K. P. Schmidt, M. Grüninger, G. S. Uhrig. 2001-09-28. Fractional and Integer Excitations in Quantum Antiferromagnetic Spin 1/2 Ladders. https://doi.org/10.1103/physrevlett.87.167204

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