Quantum Communication Complexity using the Quantum Zeno Effect

TL;DR

This paper explores how the quantum Zeno effect can reduce communication complexity in quantum information tasks, demonstrating theoretical protocols and an experimental proof of concept using qudits and entanglement.

Contribution

It introduces novel quantum protocols leveraging the quantum Zeno effect to lower communication complexity, including experimental validation.

Findings

Quantum Zeno effect enables complexity reduction in communication protocols.

Single qudit protocols achieve super-classical results.

Experimental demonstration confirms theoretical predictions.

Abstract

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.