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arXiv · 2509.20962

Distillation of supersinglet states

Saeed Ahmad·Shuang Li·Jonathan Raghoonanan·Kaixuan Zhou·Valentin Ivannikov·Tim Byrnes
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Abstract

We introduce an entanglement distillation (purification) protocol for supersinglet states composed of N qubits. The supersinglet state we target is a total spin zero state with zero spin variance, and has a fully entangled structure involving all qubits. In our distillation protocol, three copies of an initial spin zero state are measured in the local total spin basis such that a higher fidelity supersinglet state is generated upon postselection. The initial state can be prepared using conventional Bell state distillation methods distributed in a way to target the supersinglet symmetries. The protocol uses only local operations and classical communications, and is suitable for long-distance applications such as quantum clock synchronization and cryptography, and avoids a high dimensional Schur transform such that it can be used for tasks such as quantum metrology.

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Saeed Ahmad, Shuang Li, Jonathan Raghoonanan, Kaixuan Zhou, Valentin Ivannikov, Tim Byrnes. 2025-09-25. Distillation of supersinglet states. https://arxiv.org/abs/2509.20962

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