Source-linked AI summary
Quantum Reading of a Classical Digital Memory
Stefano Pirandola
TL;DR
The paper studies whether digital-memory bits encoded by two reflectivities can be read more effectively with non-classical light at fixed mean photon number. It models readout as channel discrimination and shows that EPR-correlated transmitters outperform classical sources, especially for few photons and high reflectivities, with implications for optical-memory technologies.
Problem
The paper asks whether non-classical light can retrieve more information from digital-memory cells than classical light when the mean irradiated photon number is fixed.
Method
The paper models each reflectivity as an attenuator channel and compares classical transmitters with EPR transmitters using signal-idler correlations.
Results
Few-photon, high-reflectivity memories show positive information gain for EPR transmitters, with gains exceeding 0.5 bit per cell in some cases.
Takeaways & Limitations
Quantum reading can improve digital-memory readout and may support applications in optical disks, barcodes, data-transfer rates, and storage capacities.
Takeaways & Limitations
The classical comparison excludes transmitters with bandwidth above a model-dependent maximum M* because they are considered not meaningful for the model.
Abstract
from arXiv · showhide
We consider a basic model of digital memory where each cell is composed of a reflecting medium with two possible reflectivities. By fixing the mean number of photons irradiated over each memory cell, we show that a non-classical source of light can retrieve more information than any classical source. This improvement is shown in the regime of few photons and high reflectivities, where the gain of information can be surprising. As a result, the use of quantum light can have non-trivial applications in the technology of digital memories, such as optical disks and barcodes.