Portal de Periódicos da CAPES

Mott-insulator–to–superconductor transition in a two-dimensional superlattice

2015; American Physical Society; Volume: 92; Issue: 1 Linguagem: Inglês

10.1103/physreva.92.013601

1538-4446

Rubem Mondaini, Predrag Nikolić, Marcos Rigol,

Quantum, superfluid, helium dynamics

We use quantum Monte Carlo and exact diagonalization calculations to study the Mott-insulator to superconductor quantum phase transition in a two-dimensional fermionic Hubbard model with attractive interactions in the presence of a superlattice potential. The model introduced offers unique possibilities to study such transitions in optical lattice experiments. We show that, in regimes with moderate to strong interactions, the transition belongs to the 3D-XY universality class. We also explore the character of the lowest energy charge excitations in the insulating and superconducting phases and show that they can be fermionic or bosonic depending on the parameters chosen.