A special class of states in the self-consistent mean field approximation

Lukáš Kopnický, R. Hlubina

Amperean pairing states, which represent a special case of pair-density-wave (PDW) states with members of the Cooper pair carrying equal momenta, offer a promising description of the pseudogap phase of the cuprates. It has been suggested that such states may develop in systems with current-current interactions; here we check this proposal by a fully self-consistent mean-field analysis. We find that previous non-self-consistent theories have correctly identified the essential physical properties of the Amperean states. However, we find that Amperean pairing states are not optimal within the class of PDW states and our lowest-energy solutions do not fit the pseudogap phenomenology. A model-independent interpretation of the Fermi arcs is presented as well.

Ahmet Elçi

Lorenz S. Cederbaum, Alexej I. Streltsov

Self-consistent excited states of condensates are solutions of the Gross-Pitaevskii (GP) equation and have been amply discussed in the literature and related to experiments. By applying a recently introduced more general mean field which includes the GP one as a special case, we find a new class of self-consistent excited states. In these states macroscopic numbers of bosons reside in different one-particle functions, i.e., the states are fragmented. Still, a single chemical potential is associated with the condensate. A numerical example is presented, illustrating that the energies of the new, fragmented states are much lower than those of the GP excited states, and that they are stable to variations of the particle number and shape of the trap potential.

Lizeng Zhang, Michael Ma, Fu‐Chun Zhang

Using a self-consistent mean-field theory, where the anyon gauge field is approximated by its expectation value, we obtain a linear excitation spectrum for noninteracting anyon systems. The sound velocity is found to be \ensuremath{\surd}3 /2 of the value obtained by the random-phase approximation. The uniform liquid state of the anyon gas is shown to be locally stable against solid formation.

Sara Cruz-Barrios