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Pollmann, F; Fulde, P; Shtengel, K
Physical review letters, 04/2008, Letnik: 100, Številka: 13Journal Article
We study strongly correlated electrons on a kagome lattice at 1/6 (and 5/6) filling. They are described by an extended Hubbard Hamiltonian. We are concerned with the limit |t|<<V<<U with a hopping amplitude t, nearest-neighbor repulsion V, and on-site repulsion U. We derive an effective Hamiltonian and show, with the help of the Perron-Frobenius theorem, that the system is ferromagnetic at low temperatures. The robustness of ferromagnetism is discussed and extensions to other lattices are indicated.
