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arXiv · 2606.26084

Operational certification of nonclassicality in arbitrary quantum states from few copies

Sudip Chakrabarty·Bivas Mallick·Ananda G. Maity·A. S. Majumdar
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Abstract

States with negative Wigner functions constitute a fundamental nonclassical resource underlying quantum advantage. However, their experimental certification typically relies on reconstructing the full phase-space distribution, resulting in a prohibitive measurement overhead for arbitrary quantum states. In this letter, we overcome this limitation by introducing Wigner moments, a family of global phase-space quantities that admit an exact multicopy realization as parity expectation values, and are therefore directly measurable from only a modest number of state copies. This operational correspondence enables systematic hierarchies of detection criteria together with experimentally accessible lower bounds on the logarithmic Wigner negativity, and constitutes a genuine measure of nonclassicality. Numerical benchmarking of our protocol reveals a substantial reduction in copy budget relative to conventional Wigner tomography, establishing Wigner moments as an efficient framework for certifying continuous-variable quantum resources such as genuine multipartite entanglement.

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Sudip Chakrabarty, Bivas Mallick, Ananda G. Maity, A. S. Majumdar. 2026-06-24. Operational certification of nonclassicality in arbitrary quantum states from few copies. https://arxiv.org/abs/2606.26084

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