Work

Quantum steering in networks: Measurement-device-independent detection, continuous variables, and practical Gaussian schemes

Year: 2026

Type: preprint

Abstract: We consider quantum steering certification in multipartite networks, with a focus on minimal trust scenarios: all-except-one parties are untrusted and treated device-independently. We show that it is always possible to lift steering certification to the measurement-device-independent regime, in which even the (last) trusted party can treat their local hardware as a black-box, except for a set of fiduciary quantum states used as the inputs to the experiment. This holds both for finite-dimensional systems as well as for bosonic continuous-variable systems, which we characterize in terms of semi-quantum games in the bipartite case. Additionally, we introduce measurement-device-independent network steering protocols based entirely on Gaussian operations -- which cannot be used for fully device-independent protocols, and thus become instead a viable option for minimal trust certification as soon as a single trusted input is inserted in the network. Our results present a basis for steering-based applications (such as randomness generation) with minimal trust beyond full nonlocality and with feasible experimental requirements.

Source: arXiv (Cornell University)

DOI: 10.48550/arxiv.2606.25690

Authors: Hu, Shao-Hua, Hsieh, Chung-Yun, Ku, Huan-Yu, Lee, Ray-Kuang, Abiuso, Paolo

Institutions: National Tsing Hua University, University of Bristol, National Taiwan Normal University, Austrian Academy of Sciences

Language: English

Topic: Quantum Information and Cryptography

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: green

Funders: Leverhulme Trust, Austrian Science Fund, National Science and Technology Council

Awards: Quantum Boundaries in Networks, G4019782970, Verification of quantum technologies, applications & systems

OpenAlex ID: W7165940317

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