Advances in Quantum Metrology

With the 2019 revision of the international system of units, quantum metrology has become the foundation of all physical measurements. Now, the seven SI base units are defined by fixed values of seven so-called defining constants, among them the caesium hyperfine frequency ΔνCs, Planck’s constant h, and the elementary charge e. This allows the realization in every lab of identical measurement standards, which are precise, intrinsically stable and do not require any calibration. While some quantum standards like Cs atomic clocks, Josephson voltage standards, and quantum Hall resistance standards, are already well established, others like advanced optical clocks, single electron pumps, among others, have yet to achieve practical utility. Additionally, quantum metrology enables more sensitive measurements taking advantage of quantum effects like squeezing for noise reduction, opening up applications such as ultra precise geodesy, gravitational wave detection, magnetometry, and even tests of quantum gravity. Furthermore, the advance of quantum applications like quantum computing, creates the need for a reliable metrology for such quantum systems, components, and devices.

In this special issue, we solicit submissions that address the foundations and applications of quantum-based measurements, in order to promote the further development of the field of quantum metrology.

Guest Editors: Hans Schumacher, Stefan Kueck, JT Janssen, Nenad Kralj, Helen Margolis, and Samuel Benz