Support a biquad parameter in set_exchange! to allow scalar biquadratic interactions for the special case of mode :dipole_large_S. The original plan was to avoid this, and instead use DynamicPolynomials to represent arbitrary biquadratic couplings symbolically. It's not clear whether the complexity of a full symbolic treatment justifies the benefit. We should be guiding people towards :dipole mode instead, which performs physically correct renormalizations. Nonetheless, scalar biquadratic interactions in :dipole_large_S can still be important for reproducing SpinW studies.
Support a
biquadparameter inset_exchange!to allow scalar biquadratic interactions for the special case of mode:dipole_large_S. The original plan was to avoid this, and instead use DynamicPolynomials to represent arbitrary biquadratic couplings symbolically. It's not clear whether the complexity of a full symbolic treatment justifies the benefit. We should be guiding people towards:dipolemode instead, which performs physically correct renormalizations. Nonetheless, scalar biquadratic interactions in:dipole_large_Scan still be important for reproducing SpinW studies.Resolves https://github.com/SunnySuite/Sunny.jl/issues/251.