We consider the generation of randomness based upon the observed violation of an Einstein-Podolsky-Rosen (EPR) steering inequality, known as one-sided device-independent randomness expansion. We show that in the simplest scenario -- involving only two parties applying two measurements with d outcomes each -- that there exist EPR steering inequalities whose maximal violation certifies the maximal amount of randomness, equal to log(d) bits. We further show that all pure partially entangled full-Schmidt-rank states in all dimensions can achieve maximal violation of these inequalities, and thus lead to maximal randomness expansion in the one-sided device-independent setting. More generally, the amount of randomness that can be certified is given by a semidefinite program, which we use to study the behaviour for non-maximal violations of the inequalities.
@article{arxiv.1803.05199,
title = {Maximal randomness expansion from steering inequality violations using qudits},
author = {Paul Skrzypczyk and Daniel Cavalcanti},
journal= {arXiv preprint arXiv:1803.05199},
year = {2018}
}