Two Photon Tripartite Entanglement Transfer via Time-Multiplexed Quantum Walks

TL;DR

This paper explores how entanglement can be transferred between different degrees of freedom in a photonic quantum network using time-multiplexed quantum walks, demonstrating the potential for scalable quantum information processing.

Contribution

It introduces a method to transfer entanglement from polarization to position degrees of freedom in a two-photon system using quantum walks, advancing quantum network capabilities.

Findings

Successful transfer of entanglement demonstrated via tomography and correlation measurements.

Entanglement transfer occurs between polarization and position degrees of freedom.

The approach enhances understanding of entanglement dynamics in multidimensional quantum networks.

Abstract

Photonic multidimensional quantum networks (MDQN), where individual subsystems are encoded using multiple degrees of freedom and photons, are an emerging platform for quantum algorithms because they offer high scalability. The distribution of non-classical and non-local correlations between the individual subsystems in an MDQN is of fundamental interest for many quantum protocols. Interestingly in an MDQN, the inseparability of two subsystems underlying entanglement can occur both between multiple distinct photons as well as between individual degrees of freedom associated with a single photon. In this work, we investigate the entanglement transfer enabled by the interplay of both entanglement between two distinct photons as well as inseparability between multiple degrees of freedom. For this purpose, we subject one photon of a polarization entangled two-photon pair to a discrete-time quantum walk introducing the position subsystem of the quantum walk as a third subsystem with qudit encoding. Here we study the resulting transfer of entanglement from the polarization degree of freedom, representing qubit encoding, towards the position degree of freedom, representing quidt encoding, via partial state tomography and correlation measurements.