  The quantum Zeno effect (QZE) is the phenomenon where the unitary evolution
of a quantum state is suppressed e.g. due to frequent measurements. Here, we
investigate the use of the QZE in a class of communication complexity problems
(CCPs). Quantum entanglement is known to solve certain CCPs beyond classical
constraints. However, recent developments have yielded CCPs where
super-classical results can be obtained using only communication of a single
d-level quantum state (qudit) as a resource. In the class of CCPs considered
here, we show quantum reduction of complexity in three ways: using i)
entanglement and the QZE, ii) single qudit and the QZE, iii) single qudit. The
final protocol is motivated by experimental feasibility, and we have performed
a proof of concept experimental demonstration.
