arXiv:1911.01263 · Physical review. B./Physical review. B
Scattering of spinon excitations by potentials in the one-dimensional Heisenberg model
Alexander Pavlis, X. Zotos
Abstract
By a semianalytical Bethe ansatz method and a $T$-matrix approach we study the scattering of a spinon, the elementary quantum many-body topological excitation in the one-dimensional (1D) Heisenberg model, by local and phonon potentials. In particular, we contrast the scattering of a spinon to that of a free spinless fermion in the XY model to highlight the effect of strong correlations. For the one-spinon scattering in an odd-site chain, we find regular behavior of the scattering coefficients. In contrast, in an even-site chain there is a transfer of transmission probability between the two spinon branches that grows exponentially with system size. We link the exponent of the exponential behavior to the dressed charge that characterizes the critical properties of the 1D Heisenberg model, an interplay of topological and critical properties. The aim of this study is a microscopic understanding of spinon scattering by impurities, barriers, or phonons, modeled as prototype potentials, an input in the analysis of quantum spin transport experiments.