Hoboken, NJ., January 15, 2026 - Modern physics has a problem. Its two main pillars are quantum theory and Einstein’s theory of general relativity, yet these two frameworks are seemingly incompatible. Quantum theory describes nature in terms of discrete quantum particles and interactions, while general relativity treats gravity as a smooth curvature of space and time. A true unification requires gravity itself to be quantum, mediated by particles known as “gravitons.” However, detecting even a single graviton was long thought fundamentally impossible. As a result, the problem of quantum gravity remained largely theoretical, with no experimentally grounded “theory of everything” in sight.
This situation changed very recently. In 2024, Igor Pikovski, assistant professor at Stevens Institute of Technology, and his team published a discovery in Nature Communications showing that graviton detection is, in fact, possible. “For a long time, graviton detection was considered so hopeless that it was not treated as an experimental problem at all,” says Pikovski. “What we found is that this conclusion no longer holds in the era of modern quantum technology.”
The key is a new perspective that synthesizes two major experimental advances. The first is the detection of gravitational waves: ripples in space-time produced by collisions of black holes or neutron stars. Predicted by Einstein over a century ago, gravitational waves were first observed in 2015 and are now detected routinely, opening an entirely new window onto the universe. If gravity ultimately obeys quantum physics, gravitational waves would be described as vast collections of gravitons acting in concert, appearing indistinguishable from a classical wave in current observations.
The second advance comes from quantum engineering. Over the past decade, physicists have learned how to cool, control, and measure increasingly massive systems in genuine quantum states, bringing quantum phenomena far beyond the atomic scale. In a landmark experiment in 2022, the laboratory of Jack Harris, professor at Yale University, demonstrated control and measurement of individual vibrational quanta of superfluid helium weighing over a nanogram.
Pikovski realized that if these two capabilities are combined, it becomes possible to absorb and detect a single graviton; a passing gravitational wave can, in principle, transfer exactly one quantum of energy (i.e. a single graviton) into a sufficiently massive quantum system. The resulting energy shift is small but can be resolved. The true difficulty is that gravitons almost never interact with matter. But for quantum systems at the kilogram scale - rather than the microscopic scale - exposed to intense gravitational waves from merging black holes or neutron stars, absorbing a single graviton becomes possible.
Building on this recent discovery, Pikovski and Harris have now teamed up to construct the world’s first experiment explicitly designed to detect individual gravitons. With support from the W. M. Keck Foundation, the team is developing a superfluid-helium resonator on the centimeter scale, approaching the regime required to absorb single gravitons from astrophysical gravitational waves.
“We already have the essential tools,” says Harris. “We can detect single quanta in macroscopic quantum systems. Now it’s a matter of scaling.”
The experiment aims to immerse a gram-scale cylindrical resonator in a superfluid-helium container, cool the system to its quantum ground state, and use laser-based measurements to detect individual phonons - the vibrational quanta into which gravitons are converted. The detector builds on systems already operating in the Harris laboratory, but pushes them into a new regime, scaling the mass to the gram level while preserving exquisite quantum sensitivity. Demonstrating the successful operation of this platform will establish a blueprint for a next iteration that can be scaled to the sensitivity required for direct graviton detection, opening a new experimental frontier in quantum gravity.
“Quantum physics began with experiments on light and matter,” says Pikovski. “Our goal now is to bring gravity into this experimental domain, and to study gravitons the way physicists first studied photons over a century ago.”
About Stevens Institute of Technology
Stevens is a premier, private research university situated in Hoboken, New Jersey. Since our founding in 1870, technological innovation has been the hallmark of Stevens’ education and research. Within the university’s three schools and one college, more than 8,000 undergraduate and graduate students collaborate closely with faculty in an interdisciplinary, student-centric, entrepreneurial environment. Academic and research programs spanning business, computing, engineering, the arts and other disciplines actively advance the frontiers of science and leverage technology to confront our most pressing global challenges. The university continues to be consistently ranked among the nation’s leaders in career services, post-graduation salaries of alumni and return on tuition investment.
About the W. M. Keck Foundation
The W. M. Keck Foundation was established in 1954 in Los Angeles by William Myron Keck, founder of The Superior Oil Company. One of the nation’s largest philanthropic organizations, the W. M. Keck Foundation supports outstanding science, engineering and medical research. The Foundation also supports undergraduate education and maintains a program within Southern California to support arts and culture, education, health and community service projects.