Quantum Reading of Unitary Optical Devices

TL;DR

This paper develops optimal quantum strategies for reading classical information from optical memories with minimal energy, demonstrating significant energy savings over classical methods and proposing feasible experimental implementations.

Contribution

It introduces optimal quantum reading strategies for unitary optical memories, improving energy efficiency and providing practical experimental proposals.

Findings

Quantum reading reduces energy consumption significantly.

Optimal strategies outperform classical coherent probes.

Feasible experimental setups are proposed.

Abstract

We address the problem of quantum reading of optical memories, namely the retrieving of classical information stored in the optical properties of a media with minimum energy. We present optimal strategies for ambiguous and unambiguous quantum reading of unitary optical memories, namely when one's task is to minimize the probability of errors in the retrieved information and when perfect retrieving of information is achieved probabilistically, respectively. A comparison of the optimal strategy with coherent probes and homodyne detection shows that the former saves orders of magnitude of energy when achieving the same performances. Experimental proposals for quantum reading which are feasible with present quantum optical technology are reported.