Implementation of one-dimensional quantum walks on spin-orbital angular momentum space of photons

TL;DR

This paper proposes a simple and efficient scheme for implementing one-dimensional quantum walks using the spin and orbital angular momentum of photons, leveraging q-plates to control photon states without complex interferometers.

Contribution

It introduces a novel scheme for quantum walks on photon spin-orbital angular momentum space using q-plates, simplifying the implementation process.

Findings

Scheme enables quantum walks on infinite OAM space controlled by SAM.

Uses q-plates to avoid complex interferometers, increasing efficiency.

Potential for high-dimensional quantum information processing.

Abstract

Photons can carry spin angular momentum (SAM) and orbital angular momentum (OAM), which can be used to realize a qubit system and a high-dimension system respectively. This spin-orbital system is very suitable for implementing one-dimensional discrete-time quantum random walks. We propose a simple scheme of quantum walks on the spin-orbital angular momentum space of photons, where photons walk on the infinity OAM space controlled by their SAM. By employing the recent invention of an optical device, the so-called 'q-plate', our scheme is more simple and efficient than others because there is no Mach-Zehnder interferometer in the scheme.