Physicists at the University of Colorado Boulder have developed a pioneering quantum device capable of measuring acceleration in three dimensions. Using a cloud of ultracold atoms and advanced laser manipulation, the team has built a compact atom interferometer that may redefine how vehicles navigate—without relying on GPS.
A new kind of interferometer
The study, titled “Vector atom accelerometry in an optical lattice”, was recently published in Science Advances. It introduces a sensor that uses six finely tuned lasers to suspend tens of thousands of rubidium atoms in space, then manipulate them to detect acceleration. This new type of atom interferometer, developed with the help of machine learning, can measure motion in three directions simultaneously—something previously thought impossible.
“Traditional atom interferometers can only measure acceleration in a single dimension, but we live within a three-dimensional world,” explained graduate student Kendall Mehling, a co-author on the paper. “To know where I’m going, and to know where I’ve been, I need to track my acceleration in all three dimensions.”
Why atoms?
While current navigation tools rely on GPS and classical accelerometers, these traditional sensors degrade over time due to environmental factors and mechanical wear. Quantum systems based on atoms offer a potential alternative. As Mehling noted, “Atoms don’t age.”
How interferometry works
Interferometers have long been used in physics to measure subtle changes by splitting and recombining waves—often beams of light. This new interferometer applies that principle to matter itself. By cooling rubidium atoms to just a few billionths of a degree above absolute zero, the team creates a Bose-Einstein Condensate (BEC), a quantum state where atoms behave as a single wave-like entity.
These atoms are then placed in a superposition, allowing them to exist in two places at once. As laser pulses push the atoms along different paths, they effectively “record” acceleration through subtle changes in their behavior. When recombined, the resulting interference pattern reveals how the atoms moved.
“Our Bose-Einstein Condensate is a matter-wave pond made of atoms, and we throw stones made of little packets of light into the pond,” said physics professor Murray Holland. “Once the ripples have spread out, we reflect them and bring them back together where they interfere.”
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AI-guided motion sensing
The precision of this device relies heavily on artificial intelligence. Holland’s team used machine learning to automate the complex process of adjusting the lasers needed to control the atoms. This computer-guided system allows for precise measurement of accelerations thousands of times smaller than Earth’s gravity.
Despite its sophistication, the apparatus is compact, fitting on a lab bench the size of an air hockey table. “Even though we have 18 laser beams passing through the vacuum system, the experiment is small enough that we could deploy it in the field one day,” said postdoctoral researcher Catie LeDesma.
Challenges and promise
Currently, the quantum device still trails classical sensors in performance. However, its long-term advantages—such as durability, accuracy, and the ability to function without satellite infrastructure—make it promising for applications in submarines, spacecraft, and remote terrestrial environments.
The project has already received significant support, including a $5.5 million grant from NASA through the Quantum Pathways Institute in 2023. The team is actively working to improve the sensor’s capabilities and expand its potential uses.
As Holland put it, “We’re not exactly sure of all the possible ramifications of this research, because it opens up a door.” While still in its experimental phase, this technology could fundamentally change how we think about motion, navigation, and the timeless reliability of atoms in a quantum world.
