| The well known theoretical proposals and experimental settings of topological superconductors are the combined system of a nanowire with Rashba spin-orbit interaction, an s-wave superconductor, and Zeeman field. The resulting state is equivalent to Kitaev chain in one dimension. On the other hand, it also can be realised by lining up magnetic impurities in conventional superconductors. We focus on the bound states around magnetic impurities in s-wave superconductors known as Shiba states. The energy of the states are in the bulk superconducting gap, and due to breaking of time reversal symmetry by magnetic impurities the states are spinpolarized. We can say the chain of impurities provides one dimensional spineless system. We calculate effective transfer hopping and pair hopping between states bound to impurities nearby. It is revealed that modulating spin ordering leads to various superconducting phases. |
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