Tunable topological states hosted by unconventional superconductors with adatoms

Abstract

Chains of magnetic atoms, placed on the surface of s-wave superconductors, have been established as a laboratory for the study of Majorana bound states. In such systems, the breaking of time reversal due to magnetic moments gives rise to the formation of in-gap states, which hybridize to form one-dimensional topological superconductors. However, in unconventional superconductors even non-magnetic impurities induce in-gap states since scattering of Cooper pairs changes their momentum but not their phase. Here, we propose a path for creating topological superconductivity, which is based on an unconventional superconductor with a chain of non-magnetic adatoms on its surface. The topological phase can be reached by tuning the magnitude and direction of a Zeeman field, such that Majorana zero modes at its boundary can be generated, moved and fused. To demonstrate the feasibility of this platform, we develop a general mapping of films with adatom chains to one-dimensional lattice Hamiltonians. This allows us to study unconventional superconductors such as Sr${}_2$RuO${}_4$ exhibiting multiple bands and an anisotropic order parameter.

8 pages, 4 figures, including supplemental material (published version)

References in corpus (9)

• Non-Abelian Anyons and Topological Quantum Computation
• Signatures of Majorana fermions in hybrid superconductor-semiconductor nanowire devices
• Majorana Fermions and a Topological Phase Transition in Semiconductor-Superconductor Heterostructures
• Observation of Majorana Fermions in Ferromagnetic Atomic Chains on a Superconductor
• Measurement-Only Topological Quantum Computation
• Observation of broken time-reversal symmetry in the heavy fermion superconductor UPt${}_3$
• Topological Yu-Shiba-Rusinov chain from spin-orbit coupling
• Majorana bound states and non-local spin correlations in a quantum wire on an unconventional superconductor
• Zeeman field induced topological phase transitions in triplet superconductors

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• Inducing chiral superconductivity on honeycomb lattice systems
• Effects of electron-electron interactions in the Yu-Shiba-Rusinov lattice model
• Topological superconductivity driven by correlations and linear defects in multiband superconductors
• Instability of Majorana states in Shiba chains due to leakage into a topological substrate
• Disorder-induced currents as signatures of chiral superconductivity