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Magnon dispersions in quantum Heisenberg ferrimagnetic chains at zero temperature

N. B. Ivanov
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Abstract

Within the Dyson-Maleev boson formalism, we study the zero-temperature magnon dispersions in a family of one-dimensional quantum Heisenberg ferrimagnets composed of two different spins $(S_1,S_2)$ in the elementary cell. It is shown that the spin-wave theory can produce precise quantitative results for the low-energy excitations. The spin-stiffness constant $ρ_s$ and the optical magnon gap $Δ$ of different $(S_1,S_2)$ ferrimagnetic systems are calculated, respectively, to second and third order in the quasiparticle interaction. The spin-wave results are compared with available numerical estimates.

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N. B. Ivanov. 2000-01-31. Magnon dispersions in quantum Heisenberg ferrimagnetic chains at zero temperature. https://doi.org/10.1103/physrevb.62.3271

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