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arXiv · 1703.04652

Finite-Temperature Dynamics and Thermal Intraband Magnon Scattering in Haldane Spin-One Chains

Jonas Becker·Thomas Köhler·Alexander C. Tiegel·Salvatore R. Manmana·Stefan Wessel·Andreas Honecker
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Abstract

The antiferromagnetic spin-one chain is considerably one of the most fundamental quantum many-body systems, with symmetry protected topological order in the ground state. Here, we present results for its dynamical spin structure factor at finite temperatures, based on a combination of exact numerical diagonalization, matrix-product-state calculations and quantum Monte Carlo simulations. Open finite chains exhibit a sub-gap band in the thermal spectral functions, indicative of localized edge-states. Moreover, we observe the thermal activation of a distinct low-energy continuum contribution to the spin spectral function with an enhanced spectral weight at low momenta and its upper threshold. This emerging thermal spectral feature of the Haldane spin-one chain is shown to result from intra-band magnon scattering due to the thermal population of the single-magnon branch, which features a large bandwidth-to-gap ratio. These findings are discussed with respect to possible future studies on spin-one chain compounds based on inelastic neutron scattering.

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Jonas Becker, Thomas Köhler, Alexander C. Tiegel, Salvatore R. Manmana, Stefan Wessel, Andreas Honecker. 2017-03-14. Finite-Temperature Dynamics and Thermal Intraband Magnon Scattering in Haldane Spin-One Chains. https://doi.org/10.1103/physrevb.96.060403

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