Using something called a quantum grid, scientists have found a clever way to measure momentum and position simultaneously without violating Heisenberg’s Uncertainty Principle. Physicists have measured both the momentum and position of a particle without violating Heisenberg’s iconic uncertainty principle.
In quantum mechanics, particles don’t have fixed properties like normal matter. They exist in a fog of possibilities until they’re measured. And when some properties are measured, others become uncertain. According to Heisenberg’s uncertainty, it’s not possible to know both the exact position of a particle and its exact momentum at the same time.
But a new study has shown a clever loophole around this limitation. Australian physicists have shown that by focusing on different quantities, known as modular observables, they can measure position and momentum simultaneously.
In physics, force is the force that causes a change in momentum and position over time. By observing how the grid pattern moves, the researchers measured the tiny shocks that the ions experience.
While the force achieved is not the lowest, it demonstrates that scientists can get extremely high sensitivity from a very basic setup. The ability to sense tiny changes has broad implications across science and technology. Ultra-precise quantum sensors could improve navigation in places where GPS doesn’t reach, such as underwater, underground, or in space. They could also improve biological and medical imaging.
Just as atomic clocks revolutionized navigation and telecommunications, quantum-enhanced sensors with extreme sensitivity could open the door to entirely new industries.
One of the cornerstones of quantum mechanics is Heisenberg’s uncertainty principle, which states that the precise position and momentum of a particle cannot be known at the same time. While this was long considered an insurmountable boundary, recent research has provided a new perspective. Australian physicists have shown that it is possible to measure both position and momentum simultaneously without violating the principle. The condition is that the observable is measured in a modular form rather than directly.
The researchers say they have not avoided uncertainty but rather reframed it. By focusing only on the necessary information, they have eliminated extra uncertainty. For example, in a ruler measurement, the main consideration is the deviation of a small part rather than the total length, which is equivalent to the modular size. The researchers focused on a single trapped ion. A single charged atom that is held in place by an electromagnetic field. They used a tuned laser to transform the ion into a quantum pattern called a grid state.
To test the technique in practice, the team trapped a single ion in an electromagnetic trap and used a laser to transform it into a quantum “grid state.” In this grid state, the particle’s wavefunction is spread out over multiple, evenly spaced peaks. As a result, uncertainty is largely confined to the gaps between the peaks. Applying a small force causes the entire grid pattern to shift. The displacement of the peaks indicates a change in position, while the slight tilt of the pattern reveals a change in momentum. In this way, it is possible to detect both changes simultaneously.
The experiment detected forces of about a newton (10 yoctonewtons). Although this is not the lowest force measurement record, achieving this sensitivity using a single atom is significant. It suggests that very subtle changes can be detected without complex and expensive instrumentation.
In the future, such quantum sensors could revolutionize a wide range of fields, from navigation to medical imaging. Just as atomic clocks transformed modern communications and navigation, ultra-sensitive sensors will open up new industrial and technological possibilities.
Source: livescience.com
