Quantum Metrology Applications

Quantum Sensing Breakthrough Sets New Standard for Light Displacement Detection Unprecedented Precision Through Photon Interference Physicists at the University of Portsmouth have made a landmark advancement in quantum sensing, achieving a new level of precision in detecting ultra-tiny spatial shifts in light—down to the nanoscale. Published in Physical Review A, the study leverages quantum interference between entangled photons to surpass the limits of classical measurement tools, marking a potential turning point for fields requiring extreme sensitivity, such as advanced materials science, metrology, and navigation. How It Works: Entangled Photons and Beam-Splitters • Photon Entanglement and Interference: The research team used pairs of entangled photons—light particles whose properties remain linked even when separated. These photons were sent through a beam-splitter that directs them along different paths. • Interference-Based Detection: The entangled photons interact in predictable but highly sensitive interference patterns. By analyzing even minute changes in these patterns, researchers can detect spatial displacements at an extraordinarily fine scale. • Beyond Classical Limits: Traditional methods struggle to maintain accuracy when displacements become extremely small or large. This quantum approach, however, maintains its precision regardless of the scale of the displacement. Applications and Scientific Impact • Characterizing Birefringent Materials: The technique has direct applications in analyzing materials that change the direction of light based on polarization—useful in optics, telecommunications, and medical imaging. • Precision Rotation Sensing: This level of displacement detection opens new doors for extremely accurate gyroscopes and navigation systems, particularly in environments where GPS isn’t available, such as deep space or underwater. • Industrial and Daily Impacts: Ultra-precise measurements are essential in semiconductor manufacturing, nanofabrication, and high-resolution imaging. This breakthrough could significantly enhance those processes, improving both product performance and measurement reliability. Why It Matters: Quantum Precision Moves Closer to Real-World Deployment This achievement demonstrates the practical power of quantum physics to revolutionize measurement science. With its ability to detect infinitesimal spatial changes using entangled photons, the Portsmouth team has brought quantum sensing closer to mainstream industrial and scientific applications. In a world increasingly defined by nanoscale engineering and quantum technologies, the ability to “see” with such clarity is more than academic—it’s foundational for future innovation. This work not only reinforces the value of quantum research but also brings us one step closer to a future where quantum sensing reshapes how we measure, navigate, and understand the physical world.

ASML makes some of the most complex machines humans have ever built. Their extreme ultraviolet (EUV) lithography systems—used to print the most advanced microchips—are a synthesis of precision optics, nanometer-scale positioning, and ultrahigh vacuum engineering. Each EUV machine is so intricate and massive that shipping one involves four Boeing 747 freighters, each carrying modularized components that will later be reassembled on-site over several months. This level of technical choreography makes a fascinating company to watch. One way to track their strategic direction is through their patent filings, which often reveal the bleeding edge of where advanced manufacturing is heading. A recent example filed by ASML and automatically tracked on the The Quantum Insider platform offers a clear signal of where things are going. The patent (EP4589629A2) describes an assessment apparatus for semiconductor inspection that embeds quantum sensors—specifically nitrogen-vacancy (NV) diamond sensors and atomic vapor cells—within the electron-optical systems of scanning electron microscopes . In practical terms, these sensors are being used to measure local electromagnetic fields in real time inside the lithography tool. That’s critical: slight distortions in these fields can alter the trajectory of the electron beam used for defect inspection or metrology, compromising accuracy. By integrating quantum sensors—known for their high sensitivity and immunity to 1/f noise—ASML can dynamically detect and correct for these fluctuations, either during operation (feedback mode), in between scans (feedforward mode), or via post-processing to clean up the final image . So while most people still associate quantum tech with computing or cryptography, its real-world impact is already emerging in semiconductor yield enhancement, quietly embedded inside machines that build the digital future.

Papers come in bunches :) Delighted to share the first in a series of collaborative works with Prof Saikat Guha that originated from conversations a couple of years ago—finally brought to life with our first idea! In this study, we introduce a two-stage optical sensing protocol using spatial mode demultiplexing (SPADE), which substantially improves sub-diffraction localization and brightness estimation of NV center ensembles. Our method achieves up to 6× better localization and 2× higher brightness accuracy than conventional imaging, opening pathways to atomic-scale sensing beyond the diffraction limit. It was fantastic to work with the students - Nico, Declan and Ayan! See the full paper: https://lnkd.in/gjrzs28T In another work, we demonstrate simultaneous real-time measurement of temperature and magnetic fields using NV centers in nano diamonds. This dual-sensing capability unlocks exciting opportunities—from exploring temperature-dependent magnetization in magnetic materials to advancing diagnostics in integrated circuits and cell physiology. See the full paper: https://lnkd.in/gifnQ2Hg Indian Institute of Technology, Bombay | National Quantum Mission | Qmet Tech