title: Fermi points and topological quantum phase transitions in a multi-band superconductor.
abstract: The importance of models with an exact solution for the study of materials with non-trivial topological properties has been extensively demonstrated. The Kitaev model plays a guiding role in the search for Majorana modes in condensed matter systems. Also, the sp-chain with an anti-symmetric mixing among the s and p bands is a paradigmatic example of a topological insulator with well understood properties. Interestingly, these models share the same universality class for their topological quantum phase transitions. In this work we study a two-band model of spinless fermions with attractive inter-band interactions. We obtain its zero temperature phase diagram, which presents a rich variety of phases including a Weyl superconductor and a topological insulator. The transition from the topological to the trivial superconducting phase has critical exponents different from those of Kitaev's model.
authors.affiliation: Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud, 150-Urca, Rio de Janeiro-RJ 22290-180, Brazil.
authors.forename: T O
authors.initials: TO
authors.lastname: Puel
authors.forename: P D
authors.initials: PD
authors.lastname: Sacramento
authors.forename: M A
authors.initials: MA
authors.lastname: Continentino