Researchers from the University of Sydney and RMIT University have developed a groundbreaking method for quantum measurement that effectively bypasses the limitations imposed by Heisenberg's uncertainty principle. This advancement, published in the September 24, 2025, issue of *Science Advances*, enables the simultaneous and precise determination of a particle's position and momentum, a feat previously considered fundamentally constrained by quantum mechanics.
Heisenberg's uncertainty principle, a core concept in quantum mechanics, dictates an inherent trade-off: the more precisely one measures a particle's position, the less precisely its momentum can be known, and vice versa. This principle has long presented a significant obstacle in the development of highly accurate quantum sensors. The novel technique ingeniously redistributes this inherent uncertainty, shifting it to less critical aspects of the measurement, thereby enhancing the precision with which minute changes in both position and momentum can be detected.
The scientists utilized 'grid states,' a sophisticated quantum state initially developed for error-corrected quantum computing, to achieve unprecedented measurement resolutions. This allowed them to discern uncertainties as small as half a nanometer and forces as minuscule as yoctonewtons—a force a trillionth of a trillionth of a newton. For context, measuring forces in the yoctonewton range is comparable to detecting the weight of approximately 30 oxygen molecules. Previous research has demonstrated the ability to measure forces around 42 yoctonewtons using ultracold atoms, underscoring the extreme sensitivity achievable with advanced measurement techniques.
The implications of this breakthrough are vast, promising to revolutionize fields that rely on detecting exceptionally small signals. Gravitational-wave observatories, such as LIGO, which monitor cosmic events like colliding black holes, stand to benefit significantly. The enhanced precision could lead to the development of more sensitive quantum sensors applicable in navigation, medical imaging, materials science, and astrophysics. Quantum sensors are already being explored for their potential in geology, medical diagnosis, and improving navigation systems for autonomous vehicles.
This pioneering research, a collaborative effort involving institutions across Australia and the United Kingdom, signifies a pivotal moment in quantum measurement science. It establishes a new paradigm for future sensing technologies designed to detect the faintest signals. While currently demonstrated in a laboratory setting, the potential for developing ultra-sensitive quantum sensors with broad applications in science and technology is substantial. The exploration of 'grid states' for quantum error correction, for instance, has shown promise in increasing the coherence time of quantum memory, a crucial step for advanced quantum computing. This breakthrough not only pushes the boundaries of fundamental physics but also paves the way for a new generation of measurement tools that could transform our understanding and interaction with the quantum realm.