Experimental Multi-Party Sequential State Discrimination

TL;DR

This paper reports the experimental implementation of a multi-party quantum state discrimination protocol using polarization single-photon states, demonstrating the feasibility of sequential measurements in quantum networks for information processing.

Contribution

The first experimental realization of a multi-party sequential quantum state discrimination protocol using polarization photons in an optical network.

Findings

Successful discrimination probability demonstrated across multiple parties.

Implementation over an optical network confirms practical feasibility.

Advances multi-party quantum information processing capabilities.

Abstract

Recently, a protocol for quantum state discrimination (QSD) in a multi-party scenario has been introduced [Phys. Rev. Lett. 111, 100501 (2013)]. In this protocol, Alice generates a quantum system in one of two pre-defined non-orthogonal qubit states, and the goal is to send the generated state information to different parties without classical communication exchanged between them during the protocol's session. The interesting feature is that, by resorting to sequential generalized measurements onto this single system, there is a non-vanishing probability that all observers identify the state prepared by Alice. Here, we present the experimental implementation of this protocol based on polarization single-photon states. Our scheme works over an optical network, and since QSD lies in the core of many protocols, it represents a step towards experimental multi-party quantum information processing.