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arXiv · 2303.03938

Topological Superconductivity by Engineering Noncollinear Magnetism in Magnet/ Superconductor Heterostructures: A Realistic Prescription for 2D Kitaev Model

Pritam Chatterjee·Sayan Banik·Sandip Bera·Arnob Kumar Ghosh·Saurabh Pradhan·Arijit Saha·Ashis K. Nandy
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Abstract

We report on a realistic and rather general scheme where noncollinear magnetic textures proximitized with the most common $s$-wave superconductor can appear as the alternative to $p$-wave superconductor{--}the prime proposal to realize two-dimensional (2D) Kitaev model for topological superconductors (TSCs) hosting Majorana flat edge mode (MFEM). A general minimal Hamiltonian suitable for magnet/superconductor heterostructures reveals robust MFEM within the gap of Shiba bands due to the emergence of an effective ``$p_x+p_y$"-type $p$-wave pairing, spatially localized at the edges of a 2D magnetic domain of spin-spiral. We finally verify this concept by considering Mn (Cr) monolayer grown on a $s$-wave superconducting substrate, Nb(110) under strain (Nb(001)). In both 2D cases, the antiferromagnetic spin-spiral solutions exhibit robust MFEM at certain domain edges that is beyond the scope of the trivial extension of 1D spin-chain model in 2D. This approach, particularly when the MFEM appears in the TSC phase for such heterostructure materials, offers a perspective to extend the realm of the TSC in 2D.

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Pritam Chatterjee, Sayan Banik, Sandip Bera, Arnob Kumar Ghosh, Saurabh Pradhan, Arijit Saha, Ashis K. Nandy. 2023-03-07. Topological Superconductivity by Engineering Noncollinear Magnetism in Magnet/ Superconductor Heterostructures: A Realistic Prescription for 2D Kitaev Model. https://arxiv.org/abs/2303.03938

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