Bound Entangled States Are Useful in Prepare-and-Measure Scenarios

Abstract

We show that bipartite bound entangled states make possible violations of correlation inequalities in the prepare-and-measure scenario. These inequalities are satisfied by all classical models as well as by all quantum models that do not feature entanglement. In contrast to the known Bell inequality violations from bound entangled states, we find that the violations in the prepare-and-measure scenario are sizeable and significantly noise-tolerant. Furthermore, we show that significantly stronger quantum correlations are made possible by considering bound entanglement with a larger dimension. Published by the American Physical Society 2025