Experimental realization of a generalized measuring device via a one-dimensional photonic quantum walk

TL;DR

This paper experimentally demonstrates a photonic quantum walk to perform unambiguous state discrimination and generalized measurements on single-qubit states, advancing quantum measurement techniques.

Contribution

It presents the first experimental realization of a generalized measurement via a one-dimensional photonic quantum walk, including unambiguous state discrimination.

Findings

Successful implementation of unambiguous state discrimination.

Realization of a quantum walk algorithm for positive operator value measurement.

Measurement outcomes match theoretical predictions.

Abstract

We demonstrate an implementation of unambiguous state discrimination of two equally probable single-qubit states via a one-dimensional photonic quantum walk experimentally. Furthermore we experimentally realize a quantum walk algorithm for implementing a generalized measurement in terms of positive operator value measurement on a single qubit. The measurement of the single-photons' positions corresponds to a measurement of an element of the positive operator value measurement on the polarizations of the single-photons.