Implementation of discrete positive operator valued measures on linear optical systems using cosine-sine decomposition

TL;DR

This paper presents a robust, all-optical method to implement any positive operator valued measure (POVM) in linear optical systems, enhancing quantum communication and computation capabilities.

Contribution

It introduces a novel scheme using cosine-sine decomposition to realize arbitrary POVMs in linear optical systems, enabling efficient quantum measurements.

Findings

The scheme can implement arbitrary POVMs in linear optical systems.

It is suitable for quantum state tomography.

It facilitates the preparation of arbitrary mixed states.

Abstract

Positive operator valued measurements (POVMs) play an important role in efficient quantum communication and computation. While optical systems are one of the strongest candidates for long distance quantum communication and information processing, efficient methods to implement POVMs in these systems are scarce. Here we propose an all-optical scheme to implement an arbitrary POVM using linear optical components on m-dimensional Hilbert space of internal degrees of freedom. Linear optical nature of the proposed scheme makes it efficient and robust. We show how the scheme can be applied for state tomography and for preparing arbitrary mixed states.