- What are the ground state wavefunctions of the anti-ferromagnetic (AFM) Heisenberg spin chains?
Is that which of the following? $$| ↑↓↑↓ · · · ↑↓>$$ or $$| ↓↑↓↑ . . . ↓↑>$$ or $$| ↑↓↑↓ · · · ↑↓> +| ↓↑↓↑ . . . ↓↑>$$ or $$| ↑↓↑↓ · · · ↑↓> - | ↓↑↓↑ . . . ↓↑>$$
What are the number of ground states?
What are the Neel states?