Extended high-temperature series for the Spin-Heisenberg ferromagnet

M. D. Kuz'Min (1)

1 IM2NP - Institut des Matériaux, de Microélectronique et des Nanosciences de Provence

High-temperature series for the magnetic susceptibility and hypersusceptibility of the S = 1 /2 Heisenberg ferromagnet have been extended to 14 th order in x = J/kT for four common lattices. Hence improved estimates have been deduced for the critical points, xc = 0.2491(1) (fcc), 0.3968(2) (bcc), 0.596(1) (sc), 1.124(2) (diamond), as well as for the critical exponents, γ = 1.428(3) and ∆ = 1.814(6). The latter are distinct from the respective values for the classical (S = ∞) Heisenberg model, γ ≈ 1.40 and ∆ ≈ 1.77.

Mots clés: High-temperature series; Heisenberg model; magnetic susceptibility

Domaines: Electrons fortement corrélés [cond-mat.str-el]

M. D. Kuz'Min. Extended high-temperature series for the Spin-Heisenberg ferromagnet. Philosophical Magazine Letters, 2019, 99 (9), pp.338-350. ⟨10.1080/09500839.2019.1692156⟩. ⟨hal-02390804⟩