Abstract
We propose that propagating one-dimensional Majorana fermions will develop in the vortex cores of certain iron-based superconductors, most notably . A key ingredient of this proposal is the 3D Dirac cones recently observed in photoemission experiments [P. Zhang et al., Nat. Phys. 15, 41 (2019)]. Using an effective Hamiltonian around the line we demonstrate the development of gapless one-dimensional helical Majorana modes, protected by symmetry. A topological index is derived which links the helical Majorana modes to the presence of monopoles in the Berry curvature of the normal state. We present various experimental consequences of this theory and discuss its possible connections with cosmic strings.
- Received 10 February 2019
DOI:https://doi.org/10.1103/PhysRevLett.122.207001
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