Operating a non-Hermitian atomic magnetometer with programmable digital electronics

Non-Hermitian systems with exceptional points (EPs) have attracted much attention for their potential to increase sensitivity. However, EPs are difficult to generate and control accurately in most physical systems, as they are extremely sensitive to environmental disturbances. We propose a unique non-Hermitian system formed by hybridizing digital electronics with physical sensors. The programmability of digital electronics allows EPs to be created, manipulated, and applied easily and flexibly. More interestingly, the modular design of our system facilitates coupling with various physical sensors, increasing their linear response to an EP-enhanced sublinear response. By coupling digital electronics with an atomic magnetometer, we achieved a 4.27-fold sensitivity increase for weak magnetic field measurements. Our work opens a new frontier at the junction of three active fields, namely, atomic physics, electronics, and non-Hermitian devices. The programmability, scalability, and practicality of our approach could further increase the universality, complexity, and intelligence of non-Hermitian fields. Despite several experimental studies, implementing sensing platforms based on non-Hermitian exceptional points remains challenging. Here, the authors introduce a programmable digital electronic unit design within a non-Hermitian atomic magnetometer, overcoming technical limitations and showing enhanced sensing.