Supercurrent-Induced Weyl Superconductivity

Abstract

We show that Weyl superconductivity can be induced by finite supercurrent in noncentrosymmetric spin-orbitcoupled superconductors with line nodes. We introduce a three-dimensional tight-binding model of a tetragonal superconductor in a 𝐷 + 𝑝-wave pairing state with a finite center-of-mass momentum, and elucidate that a line-nodal to point-nodal spectral transition occurs by applying an infinitesimal supercurrent. We also clarify that the higher-order effect in spin-orbit coupling is particularly important for this phenomenon. The point nodes are protected by topologically nontrivial Weyl charges, and therefore gapless arc states appear on the surface of the superconductor. Furthermore, both the positions and the Weyl charges of the point nodes depend on the direction of the current. In addition, a quantized Berry phase defined on high-symmetry planes characterizes the Weyl nodes when the in-plane supercurrent is considered. Our proposition paves a new way for controlling the superconducting gap structures by using an external field.