For a class of quantum systems that exhibit contextuality, a rigorous theoretical connection between anomalous heat flow and quantumness is established, thereby opening avenues to explore nonclassical...

New research demonstrates Quantum Networks exhibit nonclassicality beyond standard Bell tests, revealing network nonlocality even when individual nodes are classical.

Noncommutativity of states and observables is a fundamental signature of quantum theory, and a minimal requirement for nonclassicality. We provide a universal necessary and sufficient condition for pa...

Quantum 10, 2213 (2026). https://doi.org/10.22331/q-2026-09-21-2213 The possibility of nonclassicality in networks unrelated to Bell’s original eponymous theorem has recently attracted significant interest. Here, we identify a sufficient condition for being “outside the shadow of Bell’s theorem” and introduce a testable criterion capable of certifying the novelty of instances of network-nonclassicality which we call minimal network nonclassicality. We provide examples of minimally network nonclassical correlations realizable in quantum theory as well as examples coming from more exotic operational probabilistic theories. In particular, we apply these concepts to the simplest configuration of the 3-chain scenario (a.k.a. the bilocality scenario) to prove that certain correlations have escaped the shadow of Bell's theorem. While some of the examples herein are unprecedented, we also revisit more familiar examples of network nonclassicality in order to highlight the contrast between our approach versus prior approaches with respect to assessing novelty.

A nonclassicality witness in qubits now reaches 1/4, exceeding the limitations of previous structural criteria for assessing quantum behaviour. This quantification, achieved with specific POVMs and maximal dephasing, reveals nonclassicality even when standard projective measurements fail to detect it. Connecting Kolmogorov consistency with measurement unsharpness offers a new avenue for validating quantum devices.

Researchers have demonstrated that classical light can mimic the behaviour expected from quantum systems in a basic communication task, challenging our understanding of what truly constitutes quantum nonclassicality and potentially simplifying the development of secure communication technologies.

Yujie Zhang, Yìlè Yīng, and David Schmid, Quantum 10, 2180 (2026). In recent work [Phys. Rev. X 16, 021050], we proposed a unified notion of nonclassicality that applies to arbitrary processes in quantum theory, including individual quantum states, measurem…

YouTube video by iiptv

Maria Ciudad Alañón, Emanuel-Cristian Boghiu, Paolo Abiuso, and Elie Wolfe, Quantum 10, 2213 (2026). The possibility of nonclassicality in networks unrelated to Bell’s original eponymous theorem has...

Brian Doolittle, Felix Leditzky, and Eric Chitambar, Quantum 10, 2052 (2026). Quantum resources, such as entanglement or quantum communication, offer significant communication advantages in information...

Maria Ciudad Alañón, Emanuel-Cristian Boghiu, Paolo Abiuso, and Elie Wolfe, Quantum 10, 2213 (2026). The possibility of nonclassicality in networks unrelated to Bell’s original eponymous theorem has recently attracted significant interest. Here, we identify a sufficient condition for being…

Researchers demonstrate that a specially engineered quantum system, balancing both energy loss and gain, can generate stronger and more persistent non-classical quantum states than systems relying solely on loss or gain, offering advantages for practical quantum technologies.

Researchers demonstrate that the boundary between quantum and classical physics is not a fundamental law, but rather a practical limit imposed by environmental disturbances, by observing violations of a key classical principle in a large ensemble of quantum particles detectable with current technology.