Stefano Cusumano of the Università degli Studi di Napoli Federico II

I will discuss the role of non-stabilizerness (aka magic) in violating the CHSH inequality. In particular, I will discuss quantitatively the interplay between entanglement and non-stabilizer resources in violating the CHSH inequalities. I will show that, while non-stabilizer resources are necessary, they must have a specific structure, namely they need to be both asymmetric and (surprisingly) local. I will quantify the non-stabilizer resources involved and the probability of violation given the resources. I will also show how spectral quantities related to the flatness of entanglement spectrum and its relationship with non-local SE affect the CHSH inequality. Finally,  these results, together with tools from representation theory, will be used to construct a systematic way of building ensembles of states with higher probability of violation.   Based on: ArXiv:2504.03351