Detecting itinerant single microwave photons

TL;DR

This paper reviews recent developments in non-destructive microwave photon detectors using superconducting artificial atoms, highlighting their high efficiency potential and readiness for experimental implementation in quantum technologies.

Contribution

It provides a comprehensive review of theoretical proposals for microwave photon detection, emphasizing non-destructive methods with high efficiency using superconducting artificial atoms.

Findings

Detection efficiencies up to 90% are achievable with current technology.

Non-destructive detection schemes are promising for microwave quantum optics.

The reviewed proposals are ready for experimental testing.

Abstract

Single photon detectors are fundamental tools of investigation in quantum optics and play a central role in measurement theory and quantum informatics. Photodetectors based on different technologies exist at optical frequencies and much effort is currently being spent on pushing their efficiencies to meet the demands coming from the quantum computing and quantum communication proposals. In the microwave regime however, a single photon detector has remained elusive although several theoretical proposals have been put forth. In this article, we review these recent proposals, especially focusing on non-destructive detectors of propagating microwave photons. These detection schemes using superconducting artificial atoms can reach detection efficiencies of 90\% with existing technologies and are ripe for experimental investigations.