  The inequalities that separate contextual from noncontextual correlations for
the n-cycle scenario (consisting of n dichotomic observables Oj, with j = 0,
..., n-1 and such that Oj and Oj+1 are jointly measurable) have been recently
identified [arXiv:1206.3212 (2012)]. Here we report the results of an
experiment designed to reach the maximum quantum violation of these
inequalities for any even number of observables ranging from 4 to 14. The four
dimensional Hilbert space required for the test was spanned by two photonic
qubits encoded in the transversal path of photon pairs, and the joint
measurability of the observables is guaranteed by measuring correlations
between observables from different modes. Our results show contextual
correlations as predicted by quantum mechanics.
