Gaussian Quantum Reading beyond the Standard Quantum Limit

TL;DR

This paper presents an optimal Gaussian quantum reading strategy using squeezed light and homodyne detection, surpassing the Standard Quantum Limit and feasible with current technology for high-efficiency optical data retrieval.

Contribution

It introduces a new Gaussian approach for quantum reading that outperforms classical limits and is practical with existing quantum optical devices.

Findings

Outperforms the Standard Quantum Limit in quantum reading.

Effective even with optical loss.

Feasible with current quantum optical technology.

Abstract

Quantum reading aims at retrieving classical information stored in an optical memory with low energy and high accuracy by exploiting the inherently quantum properties of light. We provide an optimal Gaussian strategy for quantum reading with phase-shift keying encoding that makes use of squeezed coherent light and homodyne detectors to largely outperform the Standard Quantum Limit, even in the presence of loss. This strategy, being feasible with current quantum optical technology, represents a viable prototype for a highly efficient and reliable quantum-enhanced optical reader.