Unveiling the link between quantum ghost imaging and Grover's quantum searching algorithm

TL;DR

This paper uncovers a conceptual and operational connection between quantum ghost imaging and Grover's quantum search algorithm, demonstrating how photon correlations can be used for quantum search tasks.

Contribution

It introduces a novel link between quantum ghost imaging and Grover's algorithm, using entangled photons to encode and identify marked elements in a quantum database.

Findings

Demonstrates the encoding of database elements as photon phases

Shows how ghost imaging can implement quantum search procedures

Establishes a new perspective on quantum imaging and computing integration

Abstract

Photonic quantum technologies have become pivotal in the implementation of communication, imaging and computing modalities. Among these applications, quantum ghost imaging (GI) exploits photon correlations to surpass classical limits, with recent advances in spatial-mode encoding and phase imaging. In parallel, all-optical computing offers powerful, passive-light processing capabilities. Here, we explore the intersection of these domains, revealing a conceptual and operational link between GI and Grover's quantum search algorithm (GSA) which is designed to search for elements in an unstructured database. Here, the elements are encoded as phases in the position basis states of photons. To show this, we use entangled photon pairs, with one photon encoding the oracle features while the other photon is used to find the marked element.