Boundary-obstructed topological high-T$_c$ superconductivity in iron pnictides
| Autor: | Wu, Xianxin, Benalcazar, Wladimir A., Li, Yinxiang, Thomale, Ronny, Liu, Chao-Xing, Hu, Jiangping |
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| Rok vydání: | 2020 |
| Předmět: | |
| Zdroj: | Phys. Rev. X 10, 041014 (2020) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevX.10.041014 |
| Popis: | Non-trivial topology and unconventional pairing are two central guiding principles in the contemporary search for and analysis of superconducting materials and heterostructure compounds. Previously, a topological superconductor has been predominantly conceived to result from a topologically non-trivial band subject to intrinsic or external superconducting proximity effect. Here, we propose a new class of topological superconductors which are uniquely induced by unconventional pairing. They exhibit a boundary-obstructed higher-order topological character and, depending on their dimensionality, feature unprecedently robust Majorana bound states or hinge modes protected by chiral symmetry. We predict the 112-family of iron pnictides, such as Ca$_{1-x}$La$_x$FeAs$_2$, to be a highly suited material candidate for our proposal, which can be tested by edge spectroscopy. Because of the boundary-obstruction, the topologically non-trivial feature of the 112 pnictides does not reveal itself for a bulk-only torus band analysis without boundaries, and as such had evaded previous investigations. Our proposal not only opens a new arena for highly stable Majorana modes in high-temperature superconductors, but also provides the smoking gun evidence for extended s-wave order in the iron pnictides. Comment: 8 pages, 4 figures + supplementary materials |
| Databáze: | arXiv |
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