Abstract

Bell's theorem shows that entangled quantum particles can exhibit correlations that classical particles cannot reproduce without an additional nonlocal resource, such as communication. In this sense, quantum particles are fundamentally more nonlocal than classical ones, and entanglement becomes unavoidable in physics. Here we prove the analogous result within quantum theory itself: indistinguishable fermions transmitted through a quantum network can generate correlations that distinguishable particles or indistinguishable bosons cannot reproduce without additional communication. In the same sense, fermions are fundamentally more nonlocal than bosons or distinguishable particles, motivating fermionic anticommutation and indistinguishability as unavoidable operational resources. Our result further implies that fermions can strictly surpass all qubit-based protocols for certain distributed computing tasks, demonstrating that a complete understanding of information processing requires going beyond qubits to fermionic information carriers - febits.

Personal information

Fatemeh Moradi-Kalarde is a third-year PhD student at Inria Saclay in Paris. Her research lies at the intersection of quantum information theory and fermionic systems, with a particular focus on the operational differences between fermionic and standard quantum information theory in network scenarios, and their applications to distributed computing tasks. Before beginning her PhD, she completed a master’s degree in Optics and Photonics at KIT and EPFL, where she worked primarily on single-photon sources.

Reference

https://arxiv.org/abs/2606.12363