Heteroatomic Andreev molecule in a superconducting island-double quantum dot hybrid

Olivér Kürtössy; Mihály Bodócs; Cătălin Paşcu Moca; Zoltán Scherübl; Ella Nikodem; Thomas Kanne; Jesper Nygård; Gergely Zaránd; Péter Makk; Szabolcs Csonka

arXiv · 2407.00825

Heteroatomic Andreev molecule in a superconducting island-double quantum dot hybrid

Olivér Kürtössy·Mihály Bodócs·Cătălin Paşcu Moca·Zoltán Scherübl·Ella Nikodem·Thomas Kanne·Jesper Nygård·Gergely Zaránd·Péter Makk·Szabolcs Csonka

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Abstract

Topological superconductors (SCs) hold great promise for fault-tolerant quantum hardware, however, their experimental realization is very challenging. Recently, superconducting artificial molecules (Andreev molecules) have opened new avenues to engineer topological superconducting materials. In this work, we demonstrate a heteroatomic Andreev molecule, where two normal artificial atoms realized by quantum dots (QDs) are coupled by a superconducting island (SCI). We show that the two normal atoms strongly hybridize and form a 3-electron-based molecular state. Our density matrix renormalization group (DMRG) calculations explain quantitatively the robust binding of electrons. The tunability of the structure allows us to drive a quantum phase transition from an antiferromagnetic Andreev molecular state to a heteroatomic Andreev molecule with ferromagnetically coupled QDs using simple electrical gating.

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Olivér Kürtössy, Mihály Bodócs, Cătălin Paşcu Moca, Zoltán Scherübl, Ella Nikodem, Thomas Kanne, Jesper Nygård, Gergely Zaránd, Péter Makk, Szabolcs Csonka. 2024-06-30. Heteroatomic Andreev molecule in a superconducting island-double quantum dot hybrid. https://arxiv.org/abs/2407.00825

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