Using quantum Monte Carlo and finite-size scaling for the Hubbard model, we find evidence of a zero-temperature transition between the nonmagnetic semi-metal and an antiferromagnetic insulator in the 2D honeycomb lattice for a nontrivial value of U/t = 4.5 +/- 0.5. The corresponding transition in Hartree-Fock mean field is at U/t = 2.23, which indicates the importance of quantum fluctuations. This represents the first example of Mott-Hubbard transition in a 2D bipartite lattice. Similar transitions are predicted for special lattices in higher dimensions, in particular for the 3D diamond lattice.
Semi-metal–insulator transition of the Hubbard model in the Honeycomb lattice / Sorella, Sandro; Tosatti, E.. - In: EUROPHYSICS LETTERS. - ISSN 0295-5075. - 19:8(1992), pp. 699-704. [10.1209/0295-5075/19/8/007]
Semi-metal–insulator transition of the Hubbard model in the Honeycomb lattice
Sorella, Sandro;
1992-01-01
Abstract
Using quantum Monte Carlo and finite-size scaling for the Hubbard model, we find evidence of a zero-temperature transition between the nonmagnetic semi-metal and an antiferromagnetic insulator in the 2D honeycomb lattice for a nontrivial value of U/t = 4.5 +/- 0.5. The corresponding transition in Hartree-Fock mean field is at U/t = 2.23, which indicates the importance of quantum fluctuations. This represents the first example of Mott-Hubbard transition in a 2D bipartite lattice. Similar transitions are predicted for special lattices in higher dimensions, in particular for the 3D diamond lattice.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
