In a remarkable advancement in quantum technology, scientists from the Raman Research Institute (RRI) have developed a new quantum magnetometry technique that can measure magnetic fields in real-world environments—without the need for bulky magnetic shielding. The breakthrough has major implications for medical imaging, geophysics, space exploration, and quantum sensing.
Using a method called Raman-Driven Spin Noise Spectroscopy (RDSNS), the researchers built a compact, all-optical magnetometer capable of operating with high sensitivity in the presence of environmental noise. Unlike traditional magnetometers, which require silent labs and complex shielding, this device can be used in hospitals, factories, mines, or even in orbit.
The RDSNS technique involves analyzing the quantum “jitters” or spin noise of Rubidium atoms when exposed to a magnetic field. By shining lasers and reading the response of the atoms, the team was able to detect magnetic field strengths accurately without disturbing the atoms. The system achieved a sensitivity of 30 picotesla per root hertz at 100 Hz—matching the performance of many large lab-based systems.
What makes the device revolutionary is its large dynamic range, compact design, and resistance to electrical and mechanical interference. This allows for precise magnetic field measurements across a wide range—from extremely weak to very strong fields—making it adaptable for applications in medicine, deep-earth exploration, and space missions.
Lead researcher Sayari, a PhD student, highlighted that this innovation successfully breaks the long-standing trade-off between sensitivity and dynamic range in magnetometry. Their work, supported by India’s National Quantum Mission, was recently published in the IEEE Transactions on Instrumentation and Measurement journal.
Looking ahead, the RRI team plans to integrate squeezed light and MEMS-based miniaturization to make the device even more efficient and portable. Their ultimate goal is to use this technology to explore deeper quantum phenomena and create field-deployable quantum sensors capable of unlocking new scientific and industrial frontiers.
According to Dr. Saptarishi Chaudhuri, head of the QuMIX lab at RRI, “Our approach reflects India’s growing ambition in the global quantum technology race.” This innovation positions India among the frontrunners in developing next-generation quantum sensing tools.
