AntiferromagneticChain.md

If you feel stuck, solutions to this exercise are available here.

1. Modify Example01 for the 1D antiferromagnetic chain shown below.

note: You must change the value of J from ferromagnetic (J>0) to antiferromagnetic (J<0). In the solution, I use the value J = -1.0 meV.

Calculate and plot a cut of S(Q,E) along 100.

2. Add an easy-plane anisotropy along 100. In the soltion, I use the value D = 0.1 meV.

note: For the sublattice "Spin0", this can be accomplished by the following code:

Vector3 xhat(1.0,0.0,0.0);
builder.addInteraction(interactions.getAnisotropy("D",0.1,xhat,"Spin0"));

3. (extra) Try calculating the spherical average. Why does this fail at certain points?