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arXiv · 1812.09876

Superunsteerability as a quantifiable resource for random access codes assisted by Bell-diagonal states

C. Jebarathinam·Debarshi Das·Som Kanjilal·R. Srikanth·Debasis Sarkar·Indrani Chattopadhyay·A. S. Majumdar
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Abstract

We show how nonclassical correlations in local bipartite states can act as a resource for quantum information processing. Considering the task of quantum random access codes (RAC) through separable Bell-diagonal states, we demonstrate the advantage of superunsteerability over classical protocols assisted with two-bits of shared randomness. We propose a measure of superunsteerability, which quantifies nonclassicality beyond quantum steering, and obtain its analytical expression for Bell-diagonal states in the context of the two- and three-setting steering scenarios that are directly related to the quantum $2 \to 1$ and $3 \to 1$ RAC protocols, respectively. The maximal values of our quantifier yield the optimal quantum efficiency for both of the above protocols, thus showing that superunsteerability provides a precise characterization of the nonclassical resource for implementing RACs with separable Bell-diagonal class of states.

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C. Jebarathinam, Debarshi Das, Som Kanjilal, R. Srikanth, Debasis Sarkar, Indrani Chattopadhyay, A. S. Majumdar. 2019-07-03. Superunsteerability as a quantifiable resource for random access codes assisted by Bell-diagonal states. https://doi.org/10.1103/physreva.100.012344

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