I am currently using Spirit for atomistic spin simulations and I have a question regarding single-ion anisotropy (SIA).
Spirit defines the SIA Hamiltonian as:
H_SIA=−A(S⋅n)^2
where A is the anisotropy magnitude and n is the anisotropy axis. I would like to simulate a negative SIA by setting A<0.
Could you please advise whether Spirit allows A to be negative directly? If not, what is the recommended way to achieve the equivalent effect of a negative SIA in Spirit?
I am currently using Spirit for atomistic spin simulations and I have a question regarding single-ion anisotropy (SIA).
Spirit defines the SIA Hamiltonian as:
H_SIA=−A(S⋅n)^2
where A is the anisotropy magnitude and n is the anisotropy axis. I would like to simulate a negative SIA by setting A<0.
Could you please advise whether Spirit allows A to be negative directly? If not, what is the recommended way to achieve the equivalent effect of a negative SIA in Spirit?