Physicists from Australia and the United Kingdom have achieved a groundbreaking advancement in the realm of quantum measurement, effectively reshaping the constraints imposed by the Heisenberg uncertainty principle. This breakthrough promises to catalyze future ultra-precise sensor technologies with vast applications ranging from navigation in GPS-denied contexts to medical imaging and astrophysical observations. The Heisenberg uncertainty principle, formulated in 1927, asserts a fundamental limit to the precision with which pairs of complementary properties—such as a particle’s position and momentum—can be simultaneously known. Traditionally, enhancing the precision in one inevitably results in increased uncertainty in the other, presenting an intrinsic trade-off.
The new research, published in Science Advances, challenges this conventional wisdom by ingeniously engineering the uncertainty distribution instead of attempting to eliminate it. Led by Dr. Tingrei Tan at the University of Sydney Nano Institute and School of Physics, the team demonstrated an innovative approach that redistributes quantum uncertainty, concentrating it in large-scale, coarse variations, allowing the fine-grained details of both position and momentum to be measured with unprecedented precision at the same time. This reframing effectively “squeezes” the quantum uncertainties into aspects less relevant to the measurement goals, akin to reallocating air inside a balloon rather than trying to remove it altogether, a metaphor provided by Dr. Tan to elucidate the concept.
To further illustrate the principle, the researchers employ an intuitive analogy involving a clock with either one or two hands. A conventional clock features an hour and a minute hand, providing a balanced reading of time. However, a clock displaying only the hour hand conveys time with a coarse granularity—hours are known definitively but minutes are vague, while a minute-hand-only clock offers precise minute readings but loses track of the broader hour context. Through this ‘modular’ measurement perspective, the global information, or “which hour it is,” is sacrificed in favor of enhanced local sensitivity, enabling finer detection of subtle changes analogous to those seen in quantum systems.
This pioneering multi-parameter measurement strategy was theoretically proposed in 2017, but until now lacked experimental verification. Dr. Tan’s team bridged this gap by leveraging technological advances initially developed for fault-tolerant quantum computing. Specifically, they implemented an error-correcting code framework previously demonstrated in Nature Physics, repurposing it to create a novel quantum sensing protocol. This crossover from quantum computing to sensing exemplifies how concepts designed for robust qubit manipulation can be adapted to amplify sensor sensitivity by mitigating the impact of quantum noise.
In their experimental realization, the team utilized the delicate vibrational motion of a trapped ion, a quantum analog of a classical pendulum. The ion was prepared in so-called “grid states,” special quantum states crafted for error-correction in quantum computers. This unique state preparation allowed simultaneous enhanced measurement of both position and momentum beyond the “standard quantum limit”—a boundary representing the best precision achievable with classical sensing methods. Notably, this protocol operates fully within the confines of quantum mechanics, preserving the Heisenberg principle by redefining the parameters of uncertainty rather than violating any fundamental laws.
The significance of these findings transcends pure physics, as pinpointing extraordinarily small signal changes is a ubiquitous need across multiple scientific and technological disciplines. Quantum-enhanced sensors leveraging this technique could revolutionize navigation, particularly in environments where traditional GPS signals are inaccessible, such as deep underwater, underground, or in outer space. Beyond navigation, the technology holds immense promise in biomedical imaging, where improved resolution and sensitivity could enable earlier disease detection, and in material monitoring and gravitational system analysis, offering insights into phenomena previously obscured by noise limitations.
This research sets a new paradigm for quantum sensing, serving not as a replacement but rather as a powerful complementary tool to existing measurement approaches. As Dr. Christophe Valahu, first author and member of the University of Sydney’s Quantum Control Laboratory, highlights, the ability to forgo global information selectively while gaining exquisite sensitivity to minute changes presents unique opportunities for detecting subtle phenomena that conventional methods might miss. In this sense, the modular measurement strategy is tailored for applications where fine detail surpasses the importance of coarse data.
Moreover, the work epitomizes the fruitful synergy of collaborative research. The project brought together experimentalists from the University of Sydney with theorists from RMIT University, the University of Melbourne, Macquarie University, and the University of Bristol in the UK. This multi-institutional and international partnership underscores the accelerating pace of discovery fostered by shared expertise and resources, contributing to the vibrant and expanding quantum research landscape in Australia and beyond.
Funding support from a diverse array of bodies—including the Australian Research Council, US Office of Naval Research Global, US Army Research Office, US Air Force Office of Scientific Research, Lockheed Martin, the European Commission, Sydney Quantum Academy, and private benefactors—undergirds the project, reflecting wide recognition of its transformative potential. The results not only push the frontiers of quantum measurement science but also set the stage for technological innovation that could, over time, spawn entirely new industries centered on quantum sensing technologies.
In conclusion, this experimental milestone carving a path beyond the classical quantum measurement limits embodies the spirit of modern quantum science: a field where theoretical insights, experimental ingenuity, and cross-disciplinary collaboration intersect to harness the peculiarities of quantum mechanics for real-world benefits. As quantum-enhanced sensors emerge from laboratory curiosities to practical tools, their impact is poised to redefine standards of precision and fuel innovations in navigation, medicine, astronomy, and beyond.
Subject of Research: Quantum-enhanced multi-parameter sensing in a single mode.
Article Title: Quantum-enhanced multi-parameter sensing in a single mode.
News Publication Date: 24 September 2025.
Web References:
References:
Valahu, C. et al. “Quantum-enhanced multi-parameter sensing in a single mode.” Science Advances (2025). DOI: 10.1126/sciadv.adw9757.
Image Credits: Fiona Wolf / The University of Sydney.
Keywords: Quantum sensing, Heisenberg uncertainty principle, grid states, trapped ion, quantum measurement, quantum computing, quantum noise, ultra-precise sensors, navigation technology, quantum control, modular measurement, error correction.
