What is Heisenberg’s uncertainty principle?
Heisenberg’s uncertainty principle is one of the most fundamental ideas in quantum mechanics. At its core, it states that certain physical properties of a particle cannot both be known with unlimited accuracy at the same time. The most famous example is position and momentum: the more precisely you measure a particle’s position, the less precisely you can know its momentum, and vice versa.
This phenomenon is not a flaw of instruments or an engineering challenge that can someday be overcome; it is an inherent feature of nature, built into the mathematics of quantum mechanics.
However, the uncertainty principle extends beyond just position and momentum. Other pairs of “conjugate variables,” such as energy and time, also follow similar trade-offs. You cannot pin down both properties simultaneously with arbitrary accuracy.
In practice, this principle sets hard limits on measurement, where classical sensors and instruments, no matter how advanced, cannot bypass these limits. This is why, for example, no microscope can reveal the exact path of an electron, and why attempts to observe certain quantum states inevitably disturb them.
It is one of the reasons quantum mechanics feels so alien compared to classical physics: the uncertainty principle means that reality at the smallest scales is not just unknown, but fundamentally unknowable in the way we expect from macroscopic experience.
Reshaping Quantum Uncertainty for Next-Generation Sensors
In what could potentially change quantum mechanics forever, physicists in Australia and the UK have experimentally demonstrated a way to reshape quantum uncertainty, allowing measurements of position and momentum with a precision once considered unattainable under Heisenberg’s principle.
The new study, led by Dr. Tingrei Tan at the University of Sydney Nano Institute, takes a different approach to the issue with measurement in quantum systems. Rather than attempting to reduce uncertainty beyond the theoretical minimum, the researchers effectively redistribute it.
Using an analogy, Dr. Tan compared quantum uncertainty to air in a balloon: it cannot be removed, but it can be squeezed into regions that do not affect the desired measurement. By pushing unavoidable uncertainty into less relevant parts of position and momentum space, the fine-grained details of both properties can be measured with far greater precision.
This strategy, sometimes described in terms of “modular” measurements, trades global information for local sensitivity. For example, one can sacrifice precise knowledge of a particle’s overall position while improving the ability to detect extremely small changes in position and momentum simultaneously. In the experiment, this was implemented using trapped ions prepared in so-called “grid states” (a type of quantum state originally developed for error-corrected quantum computing).
By adapting tools from quantum computing, the researchers measured the tiny vibrational motion of a trapped ion and showed that both position and momentum could be determined with precision beyond the standard quantum limit. As co-author Professor Nicolas Menicucci of RMIT University noted, the crossover is significant: methods designed for stabilising fragile quantum computers can be repurposed to build quantum sensors capable of detecting signals that would otherwise be drowned in noise.
Potential Impact on Electronics and Sensors
If this discovery can be translated from laboratory demonstrations to practical hardware, the implications for electronics and sensor technology are substantial. By reshaping quantum uncertainty, researchers may enable measurement systems with sensitivities beyond the standard quantum limit, something classical approaches cannot achieve.
One immediate application would be in navigation systems that operate without GPS. Instead of relying on satellites, devices could use ultra-precise quantum gyroscopes and accelerometers to track position anywhere on Earth, or even in deep space, purely through internal measurement. This would be invaluable for submarines, underground facilities, spacecraft, and other environments where GPS signals are unavailable or unreliable.
The same principle could also drive advances in medical and industrial imaging, including magnetic resonance imaging (MRI), computed tomography (CT), and other diagnostic tools that all depend on detecting faint signals against heavy noise. A sensor that suppresses quantum noise in the right way could deliver higher resolution with lower energy input, reducing scan times and patient exposure. Similar gains could be expected in precision electronics for power measurement, fault detection, and materials analysis.
Another area of interest is communication technology. By detecting extremely small signal changes with unprecedented precision, quantum-enhanced sensors may allow for ultra-low-energy data transmission. This would reduce the power cost of communication systems and could open new avenues for secure quantum communication channels.
At present, the work remains confined to controlled laboratory experiments. Trapped ions and engineered grid states are far from deployable technologies. However, as with atomic clocks, which once occupied entire rooms and now fit on chips, there is a clear path from proof-of-principle physics to engineered devices. If successful, this approach to managing uncertainty could fundamentally reshape how sensors are designed and may become a cornerstone of next-generation electronics.
