%0 Journal Article
%T Axion topological field theory of topological superconductors
%A Xiao-Liang Qi
%A Edward Witten
%A Shou-Cheng Zhang
%J Physics
%D 2012
%I arXiv
%R 10.1103/PhysRevB.87.134519
%X Topological superconductors are gapped superconductors with gapless and topologically robust quasiparticles propagating on the boundary. In this paper, we present a topological field theory description of three-dimensional time-reversal invariant topological superconductors. In our theory the topological superconductor is characterized by a topological coupling between the electromagnetic field and the superconducting phase fluctuation, which has the same form as the coupling of "axions" with an Abelian gauge field. As a physical consequence of our theory, we predict the level crossing induced by the crossing of special "chiral" vortex lines, which can be realized by considering s-wave superconductors in proximity with the topological superconductor. Our theory can also be generalized to the coupling with a gravitational field.
%U http://arxiv.org/abs/1206.1407v2