Advances in quantum metrology

Paul Hockett

Since the turn of the century, the increasing availability of photoelectron imaging experiments, along with the increasing sophistication of experimental techniques, and the availability of computational resources for analysis and numerics, has allowed for significant developments in such photoelectron metrology. Volume 2, Quantum Metrology with Photoelectrons: Applications and advances discusses the fundamental concepts along with recent and emerging applications.  Volume 2 explores the applications and development of quantum metrology schemes based on photoelectron measurements. The author begins with a brief historical background on complete photoionization experiments, followed by the details of state reconstruction methodologies from experimental measurements. Three specific applications of quantum metrology schemes are discussed in detail. In addition, the book provides advances, future directions, and an outlook including

Carlton M. Caves

Jacob M. Taylor

Luca Pezzè

The article comments on a recent advance in optical quantum metrology.

Jiahao Huang, Min Zhuang, Jungeng Zhou +2 more

Abstract Quantum metrology aims to measure physical quantities based on fundamental quantum principles, enhancing measurement precision through resources like quantum entanglement and quantum correlations. This field holds promise for advancing quantum‐enhanced sensors, including atomic clocks and magnetometers. However, practical constraints exist in the four fundamental steps of quantum metrology, including initialization, sensing, readout, and estimation. Valuable resources, such as coherence time, impose limitations on the performance of quantum sensors. Machine learning, enabling learning and prediction without explicit knowledge, provides a powerful tool in optimizing quantum metrology with limited resources. This article reviews the fundamental principles, potential applications, and recent advancements in quantum metrology assisted by machine learning.

Waldemar Nawrocki