mag4.magnon.exchange
Reciprocal-space exchange matrix J(q) and its eigenvalue spectrum.
Functions
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Compute \(J_{αβ}(q) = Σ_{\text{bonds}(α,β)} JS²_n · e^{i\,q · r_{αβ}}\). |
Diagonalise the Hermitian J(q) at every q. |
- mag4.magnon.exchange.build_jq_matrices(bond_data, q_points)[source]
Compute \(J_{αβ}(q) = Σ_{\text{bonds}(α,β)} JS²_n · e^{i\,q · r_{αβ}}\).
Returns a complex array of shape
(N_q, N_sub, N_sub).
- mag4.magnon.exchange.compute_eigenvalues_all_q(Jq)[source]
Diagonalise the Hermitian J(q) at every q.
Returns a real array
(N_q, N_sub)of eigenvalues sorted descending. Used for T_c and q₀ search; the magnon dispersion uses the LSWT dynamical matrix instead (seemag4.magnon.dispersion).