Topologically Protected Landau Level in the Vortex Lattice of a Weyl Superconductor

• Published in: Physical review letters Vol. 121; no. 3; p. 037701
• Main Authors: Pacholski, M J, Beenakker, C W J, Adagideli, I
• Format: Journal Article
• Language: English
• Published: United States 20.07.2018
• ISSN: 1079-7114
• DOI: 10.1103/physrevlett.121.037701

The question whether the mixed phase of a gapless superconductor can support a Landau level is a celebrated problem in the context of d-wave superconductivity, with a negative answer: the scattering of the subgap excitations (massless Dirac fermions) by the vortex lattice obscures the Landau level quantization. Here we show that the same question has a positive answer for a Weyl superconductor: the chirality of the Weyl fermions protects the zeroth Landau level by means of a topological index theorem. As a result, the heat conductance parallel to the magnetic field has the universal value G=1/2g_{0}Φ/Φ_{0}, with Φ as the magnetic flux through the system, Φ_{0} as the superconducting flux quantum, and g_{0} as the thermal conductance quantum.