BCS surrogate models for floating superconductor-semiconductor hybrids

Superconductor-semiconductor hybrid devices, involving quantum dots interfaced with floating and/or grounded superconductors, have reached a level of complexity which calls for the development of versatile and numerically efficient modelling tools. Here, we propose an extension of the surrogate mode...

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Bibliographic Details
Published in:arXiv.org 2024-05
Main Authors: Baran, Virgil V, Paaske, Jens
Format: Article
Language:English
Subjects:
Circuit reliability
Complexity
Quantum dots
Size effects
Solvers
Superconductivity
Superconductors
Online Access:Get full text
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Summary:Superconductor-semiconductor hybrid devices, involving quantum dots interfaced with floating and/or grounded superconductors, have reached a level of complexity which calls for the development of versatile and numerically efficient modelling tools. Here, we propose an extension of the surrogate model solver for sub-gap states [Phys. Rev. B 108, L220506 (2023)], which is able to handle floating superconducting islands with finite charging energy. Upon eliminating all finite-size effects of the computationally demanding Richardson model approach, we achieve a more efficient way of calculating the sub-gap spectra and related observables without compromising their accuracy. We provide a number of benchmarks between the two approaches and showcase the versatility of the extended surrogate model solver by studying the stability of spin-triplet ground states in various tunable devices. The methods introduced here set the stage for reliable microscopic simulations of complex superconducting quantum circuits across all their relevant parameter regimes.
ISSN:2331-8422
DOI:10.48550/arxiv.2402.18357