Three-body interaction in a magnon-Andreev-superconducting qubit system: collapse-revival phenomena and entanglement redistribution

TL;DR

This paper proposes a hybrid quantum system with a three-body interaction among a magnonic mode, an Andreev spin qubit, and a superconducting qubit, demonstrating collapse-revival phenomena and entanglement redistribution at the single-quantum level.

Contribution

It introduces a novel hybrid architecture enabling strong three-body interactions among distinct quantum systems, facilitating new quantum phenomena and entanglement dynamics.

Findings

Demonstrates synchronized collapse and revival in qubit populations.

Shows continuous reorganization of entanglement during collapse.

Conserves total entanglement while redistributing between bipartite and tripartite forms.

Abstract

Three-body interactions are fundamental for realizing novel quantum phenomena beyond pairwise physics, yet their implementation -- particularly among distinct quantum systems -- remains challenging. Here, we propose a hybrid quantum architecture comprising a magnonic mode (in a YIG sphere), an Andreev spin qubit (ASQ), and a superconducting qubit (SCQ), to realize a strong three-body interaction at the single-quantum level. Leveraging the spin-dependent supercurrent and circuit-integration flexibility of the ASQ, it is possible to engineer a strong tripartite coupling that jointly excites both qubits upon magnon annihilation (or excites magnons and SCQs upon ASQ deexcitation). Through analytical and numerical studies, we demonstrate that this interaction induces synchronized collapse and revival in qubit populations when the magnon is initially prepared in a coherent state. Notably, during the collapse region -- where populations remain static -- the entanglement structure undergoes a dramatic and continuous reorganization. We show that the genuine tripartite entanglement is redistributed into bipartite entanglement between the two qubits, and vice versa, with the total entanglement conserved. These phenomena, unattainable via two-body couplings, underscore the potential of three-body interactions for exploring intrinsically new quantum effects and advancing hybrid quantum information platforms.