Kinetic ferromagnetism on a kagome lattice.
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.
Max-Planck-Institut für Physik komplexer Systeme, 01187 Dresden, Germany.
F
F
Pollmann
P
P
Fulde
K
K
Shtengel