Non-Majorana modes in diluted spin chains proximitized to a superconductor

Abstract

Spin chains proximitized with superconducting condensates have emerged as one of the most promising platforms for the realization of Majorana modes. Here, we craft diluted spin chains atom-by-atom following seminal theoretical proposal suggesting indirect coupling mechanisms as a viable route to trigger topological superconductivity. Starting from single adatoms hosting deep Shiba states, we use the highly anisotropic Fermi surface of the substrate to create spin chains characterized by different magnetic configurations along distinct crystallographic directions. By scrutinizing a large set of parameters we reveal the ubiquitous emergence of boundary modes. Although mimicking signatures of Majorana modes, the end modes are identified as topologically trivial Shiba states. Our work demonstrates that zero-energy modes in spin chains proximitized to superconductors are not necessarily a link to Majorana modes while simultaneously identifying new experimental platforms, driving mechanisms, and test protocols for the determination of topologically non-trivial superconducting phases.

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Cited by in corpus (22)

• Majorana nanowires for topological quantum computation
• Two-dimensional Shiba lattices as possible platform for crystalline topological superconductivity
• Testing the topological nature of end states in antiferromagnetic atomic chains on superconductors
• Majorana quasiparticles in atomic spin chains on superconductors
• Josephson effect in a Fibonacci quasicrystal
• Colloquium: Synthetic quantum matter in non-standard geometries
• Topological superconductivity in Fibonacci quasicrystals
• Wave-function engineering on superconducting substrates: Chiral Yu-Shiba-Rusinov molecules
• Tailoring phase transition from topological superconductor to trivial superconductor induced by magnetic textures of a spin-chain on a $p$-wave superconductor
• Systematic study of Mn atoms, artificial dimers and chains on superconducting Ta(110)
• Search for large topological gaps in atomic spin chains on proximitized superconducting heavy metal layers
• Increased localization of Majorana modes in antiferromagnetic chains on superconductors
• Observation of Yu-Shiba-Rusinov-like states at the edge of CrBr3/NbSe2 heterostructure
• Controlling Majorana hybridization in magnetic chain-superconductor systems
• Majorana-magnon interactions in topological Shiba chains
• Predicting topological invariants and unconventional superconducting pairing from density of states and machine learning
• Gate-tunable topological superconductivity in a supramolecular electron spin lattice
• Fractional Spin Quantum Hall Effect in Weakly Coupled Spin Chain Arrays
• Effects of electron-electron interactions in the Yu-Shiba-Rusinov lattice model
• Spin-resolved nonlocal transport in proximitized Rashba nanowires
• Odd-parity ground state in dilute Yu-Shiba-Rusinov dimers and chains
• Direct signatures of $d$-level hybridization and dimerization in magnetic adatom chains on a superconductor