arXiv subjects
Publications and source records attributed to P. Mironowicz.
We describe a simple and flexible method for implementing semi-definite programming relaxations for bounding the set of quantum correlations. The method relies on obtaining equality constraints from randomly sampled moment matrices and hence allows the user to easily access the set of quantum behavior in diverse operational scenarios.
We study quantum advantage in one-step rendezvous games on simple graphs analytically, numerically, and using noisy intermediate-scale quantum (NISQ) processors. Our protocols realise the recently discovered [arXiv:2207.14404] optimal bounds for small cycle graphs and cubic graphs. In the case of cycle graphs, we generalise the protocols to arbitrary graph size. The NISQ processor experiments realise the expected quantum advantage with high accuracy for rendezvous on the complete graph K3. In contrast, for the graph 2K4, formed by two disconnected 4-vertex complete graphs, the performance of the NISQ hardware is sub-classical, consistent with the deeper circuit and known qubit decoherence and gate error rates.
We theoretically introduce and experimentally demonstrate the realization of a nonclassicality test that allows for arbitrarily low detection efficiency without invoking any extra assumptions as independence of the devices. Our test and its implementation is set in a prepare-and-measure scenario with an upper limit on the communication capacity of the channel through which the systems are communicated. The essence for our novel test is the use of two preparation and two measurement devices, which are randomly paired in each round. Our work opens up the possibility of experimental realizations of device independent protocols with current off-the-shelf technology.