Last Updated on June 12, 2025 by Sushanta Barman
In a groundbreaking advancement, researchers have developed an ultrasensitive quantum sensor capable of detecting electric fields with unprecedented precision. Published in the prestigious journal Nature Physics, the research introduces a novel technique using a single trapped ion combined with a magnetic field gradient to measure electric fields, achieving record sensitivities that surpass current quantum technologies.
The collaborative effort involved physicists from the Sussex Centre for Quantum Technologies at the University of Sussex, University College London, and Universal Quantum Ltd. in the UK.
Typically, electric field detection using quantum systems faces limitations due to the weak coupling between the internal spin states of an ion and external electric fields. To overcome this challenge, the team introduced a magnetic field gradient, effectively converting the impact of the electric field into measurable changes in the ion’s spin state energy levels. This innovative approach enabled the scientists to apply established magnetometry techniques for highly sensitive electrometry.
Practically, the scientists confined a single ytterbium ion (\(^{171}Yb^+\)) in an electromagnetic trap. Applying electric fields displaced the ion slightly within the magnetic field gradient, shifting the energy levels of its internal spin states. By carefully measuring these shifts, the researchers detected extremely subtle changes in the electric fields.
The sensor demonstrated remarkable sensitivity, capable of detecting electric fields as small as 960 microvolts per meter at frequencies near 5.8 Hz. For DC fields, the sensitivity reached an unprecedented 1.97 millivolts per meter per square root of hertz. Furthermore, the researchers showed that their sensor could analyze electric field noise, opening new pathways for applications in environmental monitoring, geological surveys, and even medical imaging.
The authors emphasize that the sensor provides unprecedented capabilities for measuring electric fields, especially in frequency ranges that have traditionally posed challenges for quantum electrometers.
The implications of this discovery are extensive. The researchers have identified a set of hardware modifications “capable of achieving a further improvement in sensitivity by up to six orders of magnitude,” paving the way for revolutionary applications in fields such as biomedical research, particle physics, and gravitational wave detection.
Future research will focus on enhancing the system’s sensitivity further, incorporating additional quantum techniques, and exploring practical deployments of this technology. This discovery marks a significant step forward in quantum sensing, promising substantial impacts across various scientific and technological domains.
Read the full article: F. Bonus et al., “Ultrasensitive single-ion electrometry in a magnetic field gradient,” Nat. Phys. (2025). https://doi.org/10.1038/s41567-025-02887-9
I am a senior research scholar in the Department of Physics at IIT Kanpur. My work focuses on ion-beam optics and matter-wave phenomena. I am also interested in emerging matter-wave technologies.
