V-MAG

V-MAG pioneers a new class of quantum magnetometer, based on spatially shaped light-atom interaction. From migratory birds and honeybees to nuclear submarines and space shuttles, magnetometry, or the measurement of the magnitude and direction of magnetic fields, can be found all throughout natural and technological domains. As such, it is both a highly prized and well researched commodity. And yet, the sheer diversity of application complects many different demands and has thus resulted in a multitude of approaches, each offering differing optimisations and compromises. The aim of V-MAG is the development of structured light atomic magnetometers, merging expertise from quantum magnetometry, structured light, cavity QED and quantum engineering. With this project we will bring state-of-the-art magnetometric enhancements demonstrated in bulky unoptimised cold-atom experiments into the domain of practical and commercial human-oriented environments. Optically pumped magnetometers present an attractive technological alternative to cryogenic, superconducting magnetic field sensors. They make use of the unique sensitivity of, for example, alkali atoms to optical and magnetic fields and operate by generating atomic polarization with polarised light and measuring its response to the magnitude and direction of an external magnetic field. To date, all commercial devices operate with homogeneously polarised pump light. We will use state-of-the-art technology to design vector light that is correlated in its spatial and polarisation degrees of freedom, allowing us to imprint spatially varying optical polarisation onto atomic spin polarisation patterns. The added spatial degree of freedom provided by structured vector light can be utilised to improve temporal and spatial resolution. This advantage will be further enhanced by the implementations with custom-designed cavities. Our magnetometers will be realised as compact and portable vapour cell systems, and in hollow-core photonic crystal fibres (HCPCFs), filled with atomic vapours, which may even support wearable devices: with potential application in state-of-the-art navigation and non-invasive medical diagnostics. Our V-MAG magnetomers will be subjected to realistic calibration and testing in a full field environment against scientific geomagnetic sensors. V-MAG aims to explore and demonstrate the resulting extended functionality compared to conventional optically pumped atomic magnetometers, addressing the following challenges: the capability to measure 3D vector magnetic field direction in a single-axis geometry, to distinguish between bias and gradient magnetic fields, and to detect time-varying magnetic fields. Taken together, these objectives will establish a baseline for the technological development of all-optical vector magnetometry based on complex vector light with spatially varying polarisation, offering an attractive tool with wide-ranging applications in physics, geophysics, biology, geophysics, medicine, navigation and defence.