| year |
2016 |
| author(s) |
K. Pöyhönen, A. Westström, T. Ojanen |
| title |
Topological superconductivity in ferromagnetic atom chains beyond the deep-impurity regime |
| document type |
Paper |
| source |
physical review b 93 1 |
| doi |
10.1103/PhysRevB.93.014517
|
| EMP/Horizon2020 |
This publication does not include a EMP/Horizon2020 acknowledgement. |
| abstract |
Recent developments in the search for topological superconductivity have brought lattices of magnetic adatoms on a superconductor into intense focus. In this work we will study ferromagnetic chains of adatoms on superconducting surfaces with Rashba spin-orbit coupling. Generalizing the deep-impurity approach employed extensively in previous works to arbitrary subgap energies, we formulate the theory of the subgap spectrum as a nonlinear matrix eigenvalue problem. We obtain an essentially analytical description of the subgap spectrum, allowing an efficient study of the topological properties. Employing a flat-band Hamiltonian sharing the topological properties of the chain, we evaluate the Z-valued winding number and discover five distinct topological phases. Our results also confirm that the topological band formation does not require the decoupled Shiba energies to be fine-tuned to the gap center. We also study the properties of Majorana bound states in the system. |
