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arXiv:1812.10155 · Physical review. B./Physical review. B

Thermodynamics and spin mapping of quantum excitations in a Heisenberg spin heptamer

A. Roxburgh, Jason T. Haraldsen

Published Dec 20, 2018• 5 citations
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Abstract

In this study, we examine the thermodynamics and spin dynamics of spin-1/2 and spin-3/2 heptamers. Through an exact diagonalization of the isotropic Heisenberg Hamiltonian, we find the closed-form, analytical representations for thermodynamic properties, spin excitations, and neutron-scattering structure factors. Furthermore, we investigate the clusterlike excitations of quantum spin heptamer in the three-dimensional pyrochlore lattice material ${\mathrm{MgCr}}_{2}{\mathrm{O}}_{4}$. Using a spin mapping of the spin-1/2 heptamer excitations, the calculated structure factors of the spin-3/2 heptamer are to be determined, which provides clarification for the spin excitations in ${\mathrm{MgCr}}_{2}{\mathrm{O}}_{4}$. Overall, this study demonstrates the ability to use the spin mapping of structure factors for small spin systems to analyze more complex structures.

DOI
10.1103/physrevb.98.214434

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