Optically Pumped Magnetometers and Their Applications

Dear Colleagues,

Atomic magnetometers (AMs), optically pumped magnetometers (OPMs), or optical quantum sensors (OQSs) find many applications in science and the industry. Perhaps the most popular and promising, in terms of potential in achieving a real breakthrough in neuroimaging, are applications in recording the magnetic field generated by the brain, magnetoencephalography (MEG). OPMs can replace the state-of-the-art superconducting quantum interference devices (SQUIDs), saving cost and making this powerful method of brain imaging more accessible by avoiding the need for expensive liquid helium. Several companies are already working on manufacturing single-channel sensors that can be combined into arrays on helmets, and it is also potentially possible to realize multichannel sensors in large alkali-metal cells with a buffer gas. Magnetocardiography (MCG) is another promising direction for replacing SQUIDs, because the need for cryogens is a significant impediment, and OPMs have recently been shown to be able to operate without shielding, provide a platform for medical MCG screening. Apart from low-frequency applications in MEG and MCG, OPMs can be used as a radiofrequency magnetic field detector in magnetic resonance imaging (MRI), nuclear magnetic resonance (NMR), and nuclear quadrupole resonance (NQR) applications. Subfemtatesla sensitivity and noncryogenic operation are important attributes that could aid in the realization of novel methods of MRI and NMR at ultra-low fields, or enable more sensitive NQR detection. Arrays of sensors can be valuable for obtaining parallel MRI and accelerating imaging. In fundamental science, OPMs are gaining momentum in applications related to axion and dark matter search. While their application is the main driver of interest in OPMs, the investigation of their principles and discovery of novel methods for ultra-sensitive magnetic field measurements in a broad range of frequencies is also a very fascinating research field. Quantum sensing approaches are examples of nontrivial physics involving OPMs. This Special Issue aims to cover the abovementioned topics and others related to OPM applications, experiments with OPMs, ideas for novel types of OPMs, and OPM theory.

Dr. Igor Mykhaylovych Savukov
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Atoms is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1500 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• atomic magnetometer
• optically pumped magnetometer
• optical quantum sensor
• MEG
• MRI
• non-cryogenic magnetometer
• photon-shot noise
• spin-projection noise
• spin squeezing
• ultra-sensitive magnetometer
• axion
• exotic spin interaction
• vapor-cell magnetometer