Ferromagnetic ground states of the Hubbard model on a complete graph
نویسنده
چکیده
We use group theory to derive the exact analytical expression of the ferromagnetic ground states of the Hubbard model on a complete graph for arbitrary lattice sites f and for arbitrary fillings N . We find that for t > 0 and for N = f + 1 the ground state is maximally ferromagnetic with total spin S = (f − 1)/2. For N > f + 1 the ground state is still ferromagnetic but becomes degenerate with respect to S. ∗ Email:[email protected]
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