Under suitable conditions, the Hamiltonian of a gas of cold bosonic atoms inside a rotating optical lattice can be mapped onto that of a frustrated Bose-Hubbard model. Here, the role of magnetic frustration is played by the angular frequency of rotation of the lattice. The system can be fully frustrated at experimentally attainable values of the frequency of rotation, and a superlattice of vortices appears in the ground state. This has several implications on observable quantities such as the superfluid density and the momentum distribution function. In the limit of large on-site occupation and in dimensionality D >= 2, the system can be mapped into an array of Josephson junctions in a magnetic field.
Frustration of a Bose gas inside an optical lattice
M Polini;
2004
Abstract
Under suitable conditions, the Hamiltonian of a gas of cold bosonic atoms inside a rotating optical lattice can be mapped onto that of a frustrated Bose-Hubbard model. Here, the role of magnetic frustration is played by the angular frequency of rotation of the lattice. The system can be fully frustrated at experimentally attainable values of the frequency of rotation, and a superlattice of vortices appears in the ground state. This has several implications on observable quantities such as the superfluid density and the momentum distribution function. In the limit of large on-site occupation and in dimensionality D >= 2, the system can be mapped into an array of Josephson junctions in a magnetic field.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
