Two of the most intriguing features of quantum physics are the uncertainty principle and the occurrence of nonlocal correlations. The uncertainty principle states that there exist pairs of incompatible measurements on quantum systems such that their outcomes cannot both be predicted. On the other hand, nonlocal correlations of measurement outcomes at different locations cannot be explained by classical physics, but appear in the presence of entanglement. Here, we show that these two fundamental quantum effects are quantitatively related. Namely, we provide an entropic uncertainty relation for the outcomes of two binary measurements, where the lower bound on the uncertainty is quantified in terms of the maximum Clauser–Horne–Shimony–Holt value that can be achieved with these measurements. We discuss applications of this uncertainty relation in quantum cryptography, in particular, to certify quantum sources using untrusted devices.
On a related topic, Oppenheim and Wehner @cite_11 ,| ,for a class of generalized physical theories that includes quantum mechanics and classical theory ,| ,showed that the presence of uncertainty, via steering, directly limits the maximally achievable nonlocality. Our result can be seen as complementary to theirs, as we show that in order to achieve a certain nonlocality, at least some specific amount of uncertainty is necessary.
@cite_11
2015389932
Two central concepts of quantum mechanics are Heisenbergs uncertainty principle and a subtle form of nonlocality that Einstein famously called spooky action at a distance. These two fundamental features have thus far been distinct concepts. We show that they are inextricably and quantitatively linked: Quantum mechanics cannot be more nonlocal with measurements that respect the uncertainty principle. In fact, the link between uncertainty and nonlocality holds for all physical theories. More specifically, the degree of nonlocality of any theory is determined by two factors: the strength of the uncertainty principle and the strength of a property called steering, which determines which states can be prepared at one location given a measurement at another.