Topological surface superconductivity in doped Weyl loop materials

Abstract

We study surface superconductivity involving the `drumhead' surface states of (doped) Weyl loop materials. The leading weak coupling instability in the bulk is toward a chiral superconducting order, which fully gaps the Fermi surface. In this state the surface also becomes superconducting, with $p+ip$ symmetry. We show that the surface SC state is "topological" as long as it is fully gapped, and the system traps Majoarana modes wherever a vortex line enters or exits the bulk. In contrast to true 2D $p+ip$ superconductors, these Majorana zero modes arise even in the "strong pairing" regime where the chemical potential is entirely above/below the drumhead. We also consider conventional $s$-wave pairing, and show that in this case the surface hosts a flat band of charge neutral Majorana fermions, whose momentum range is given by the projection of the bulk Fermi surface. Weyl loop materials thus provide access to new forms of topological superconductivity.

9 pages, 5 figures

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Cited by in corpus (34)

• Discovery of topological Weyl fermion lines and drumhead surface states in a room temperature magnet
• Weak-Pairing Higher Order Topological Superconductors
• Nonsymmorphic-symmetry-protected hourglass Dirac loop, nodal line, and Dirac point in bulk and monolayer $X_3$SiTe${}_6$ ($X=$ Ta, Nb)
• Topological crystalline superconductivity and second-order topological superconductivity in nodal-loop materials
• Magneto-transport properties of the "hydrogen atom" nodal-line semimetal candidates CaTX (T=Ag, Cd, X=As, Ge)
• Disorder-driven destruction of a non-Fermi liquid semimetal via renormalization group
• Weyl nodal surfaces
• Almost ideal nodal-loop semimetal in monoclinic CuTeO${}_3$ material
• Designing three-dimensional flat bands in nodal-line semimetals
• Generating quantum multi-criticality in topological insulators by periodic driving
• Signatures of Weyl fermion annihilation in a correlated kagome magnet
• Interplay between short-range correlated disorder and Coulomb interaction in nodal-line semimetals
• What's knot to like? Observation of a linked loop quantum state
• Emergent anomalies and generalized Luttinger theorems in metals and semimetals
• Signature of odd-frequency equal-spin triplet pairing in the Josephson current on the surface of Weyl nodal loop semimetals
• Exotic Superconductivity with Enhanced Energy Scales in Three Band Crossing Materials
• Large Josephson current in Weyl nodal loop semimetals due to odd-frequency superconductivity
• Weyl nodal point-line Fermion in ferromagnetic Eu${}_5$Bi${}_3$
• Magneto-transport and Shubnikov-de Haas oscillations in the layered ternary telluride Ta3SiTe6 topological semimetal
• Nodal topological superconductivity in nodal-line semimetals
• Prominent Cooper Pairing Away From the Fermi Level and its Spectroscopic Signature in Twisted Bilayer Graphene
• High-Mobility Carriers Induced by Chemical Doping in the Candidate Nodal-Line Semimetal CaAgP
• $R$RuB${}_2$ ($R$=Y, Lu), topological superconductor candidates with hourglass-type Dirac ring
• Superconductivity and a van Hove singularity confined to the surface of a topological semimetal
• Unusual Resistive Transitions in the Nodal-Line Semimetallic Superconductor NaAlSi
• Work statistics across a quantum critical surface
• Topological order in interacting semimetals
• Weyl Nodal-Ring Semimetallic Behavior and Topological Superconductivity in Crystalline Forms of Su-Schrieffer-Heeger Chains
• Broken-symmetry phases of interacting nested Weyl and Dirac loops
• Observation of a flat and extended surface state in a topological semimetal
• Quasiparticle interference and resonant states in normal and superconducting line nodal semimetals
• Fragile topology in nodal-line semimetal superconductors
• Signatures of a topological Weyl loop in Co${}_3$Sn${}_2$S${}_2$
• Surface magnon spectra of nodal loop semimetals