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arXiv · 2404.12207

Spin-1 Haldane chains of superconductor-semiconductor hybrids

Virgil V. Baran·Jens Paaske
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Abstract

We theoretically explore the possibility of realizing the symmetry-protected topological Haldane phase of spin-1 chains in a tunable hybrid platform of superconducting islands (SIs) and quantum dots (QDs). Inspired by recent findings suggesting that an appropriately tuned QD-SI-QD block may behave as a robust spin-1 unit, we study the behavior of many such units tunnel-coupled into linear chains. Our efficient and fully microscopic modeling of long chains with several tens of units is enabled by the use of the surrogate model solver [Phys. Rev. B 108, L220506 (2023); arXiv:2402.18357]. Our numerical findings indicate that the QD-SI-QD chains exhibit emblematic features of the Haldane phase, such as fractional spin-1/2 edge states and non-vanishing string order parameters, and that these persist over a sizeable region of parameter space.

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Virgil V. Baran, Jens Paaske. 2024-04-18. Spin-1 Haldane chains of superconductor-semiconductor hybrids. https://doi.org/10.1103/physrevb.110.064503

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