Intrinsic Time-reversal-invariant Topological Superconductivity in Thin Films of Iron-based Superconductors

Rui-Xing Zhang; S. Das Sarma

doi:10.1103/physrevlett.126.137001

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arXiv · 2012.13411

Intrinsic Time-reversal-invariant Topological Superconductivity in Thin Films of Iron-based Superconductors

Rui-Xing Zhang·S. Das Sarma

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Abstract

We establish quasi-two-dimensional thin films of iron-based superconductors (FeSCs) as a new high-temperature platform for hosting intrinsic time-reversal-invariant helical topological superconductivity (TSC). Based on the combination of Dirac surface state and bulk extended $s$-wave pairing, our theory should be directly applicable to a large class of experimentally established FeSCs, opening a new TSC paradigm. In particular, an applied electric field serves as a "topological switch" for helical Majorana edge modes in FeSC thin films, allowing for an experimentally feasible design of gate-controlled helical Majorana circuits. Applying an in-plane magnetic field drives the helical TSC phase into a higher-order TSC carrying corner-localized Majorana zero modes. Our proposal should enable the experimental realization of helical Majorana fermions.

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Rui-Xing Zhang, S. Das Sarma. 2021-04-11. Intrinsic Time-reversal-invariant Topological Superconductivity in Thin Films of Iron-based Superconductors. https://doi.org/10.1103/physrevlett.126.137001

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