title: Skyrmion Superfluidity in Two-Dimensional Interacting Fermionic Systems.
abstract: In this article we describe a multi-layered honeycomb lattice model of interacting fermions which supports a new kind of parity-preserving skyrmion superfluidity. We derive the low-energy field theory describing a non-BCS fermionic superfluid phase by means of functional fermionization. Such effective theory is a new kind of non-linear sigma model, which we call double skyrmion model. In the bi-layer case, the quasiparticles of the system (skyrmions) have bosonic statistics and replace the Cooper-pairs role. Moreover, we show that the model is also equivalent to a Maxwell-BF theory, which naturally establishes an effective Meissner effect without requiring a breaking of the gauge symmetry. Finally, we map effective superfluidity effects to identities among fermionic observables for the lattice model. This provides a signature of our theoretical skyrmion superfluidy that can be detected in a possible implementation of the lattice model in a real quantum system.
authors.affiliation: School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, United Kingdom.
authors.forename: Giandomenico
authors.initials: G
authors.lastname: Palumbo
authors.affiliation: Interdisciplinary Theoretical Science Research Group (iTHES), RIKEN, Wako-shi, Saitama 351-0198, Japan.
authors.forename: Mauro
authors.initials: M
authors.lastname: Cirio