Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Effect of Zeeman coupling on the Majorana vortex modes in iron-based
  topological superconductors   In the superconducting regime of FeTe$_{(1-x)}$Se$_x$, there exist two types
of vortices which are distinct by the presence or absence of zero energy states
in their core. To understand their origin, we examine the interplay of Zeeman
coupling and superconducting pairings in three-dimensional metals with band
inversion. Weak Zeeman fields are found to suppress the intra-orbital
spin-singlet pairing, known to localize the states at the ends of the vortices
on the surface. On the other hand, an orbital-triplet pairing is shown to be
stable against Zeeman interactions, but leads to delocalized zero-energy
Majorana modes which extend through the vortex. In contrast, the finite-energy
vortex modes remain localized at the vortex ends even when the pairing is of
orbital-triplet form. Phenomenologically, this manifests as an observed
disappearance of zero-bias peaks within the cores of topological vortices upon
increase of the applied magnetic field. The presence of magnetic impurities in
FeTe$_{(1-x)}$Se$_x$, which are attracted to the vortices, would lead to such
Zeeman-induced delocalization of Majorana modes in a fraction of vortices that
capture a large enough number of magnetic impurities. Our results provide an
explanation to the dichotomy between topological and non-topological vortices
recently observed in FeTe$_{(1-x)}$Se$_x$.

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The categories of this paper are: nlin
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-lat
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The categories of this paper are: chao-dyn
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The categories of this paper are: acc-phys
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The categories of this paper are: gr-qc
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The categories of this paper are: math
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The categories of this paper are: astro-ph
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The categories of this paper are: solv-int
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The categories of this paper are: hep-ph
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The categories of this paper are: q-bio
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The categories of this paper are: quant-ph
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The categories of this paper are: cs
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The categories of this paper are: supr-con
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The categories of this paper are: plasm-ph
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The categories of this paper are: eess