Work on resource theory of quantum contextuality in PRLPosted: April 12, 2018
Joint work of Profs. Barbara Amaral (Federal University of Ouro Preto & IIP-Natal), Adán Cabello (University of Sevilla), Marcelo T. Acunha (UNICAMP-Campinas), and Leandro Aolita (Federal University of Rio de Janeiro & ICTP/SAIFR-São Paulo) published in PRL:
Contextuality is a fundamental feature of quantum theory and is necessary for quantum computation and communication. Serious steps have therefore been taken towards a formal framework for contextuality as an operational resource. However, the most important component for a resource theory – a concrete, explicit form for the free operations of contextuality – was still missing. Here we provide such a component by introducing noncontextual wirings: a physically-motivated class of contextuality-free operations with a friendly parametrization. We characterize them completely for the general case of black-box measurement devices with arbitrarily many inputs and outputs. As applications, we show that the relative entropy of contextuality is a contextuality monotone and that maximally contextual boxes that serve as contextuality bits exist for a broad class of scenarios. Our results complete a unified resource-theoretic framework for contextuality and Bell nonlocality.