Scientists create quantum sound device that transforms healthcare:How ‘phonons’ work at temperatures near absolute zero and revolutionise medical diagnostics

Imagine a future where sound, instead of light, powers communication systems, helps doctors detect diseases with greater accuracy, and enables highly sensitive sensors. That future may have just moved a little closer. Scientists have developed a new quantum device that can produce precisely controlled ‘sound particles’ known as ‘phonons’ by pushing electrons through an ultra-thin crystal at temperatures just above absolute zero.
The study was carried out by researchers at McGill University in collaboration with the National Research Council of Canada, while the special material used to build the device was developed at Princeton University. What are phonons and why are they important? Phonons are tiny packets of energy that represent vibrations travelling through a material. In simple words, they are the quantum version of sound waves. Although we cannot hear them, phonons play a major role in how heat and energy move through materials. Scientists believe that if they can control phonons as precisely as they control light particles (photons), they could build an entirely new generation of advanced technologies. This is where the idea of a phonon laser comes in. Just as a regular laser emits highly controlled light, a phonon laser would generate extremely precise sound waves. How does the new quantum device work? The researchers built the device using a crystal that is only a few atoms thick. This ultra-thin material acts as a tiny pathway through which electrons can travel. When an electric current pushes the electrons through this narrow channel at extremely high speeds, the electrons release extra energy. Instead of emitting light, they produce controlled bursts of sound-like vibrations called phonons. The team found that these phonons could be generated repeatedly in a predictable and controllable way, marking an important milestone toward building practical quantum sound devices. Also read: China-linked app used to disable e-rickshaws banned:Action follows ‘Tirri Trend’ prank videos; miscreants switched off batteries via Bluetooth

Why did scientists cool the device to almost absolute zero? One of the most fascinating parts of the experiment is the temperature at which it was performed. The researchers cooled the device to between 10 millikelvin and 3.9 Kelvin, which is only a tiny fraction above absolute zero (-273.15°C). At such incredibly low temperatures, almost all thermal activity disappears. Electrons become much more organised, allowing scientists to observe delicate quantum effects that would normally remain hidden. The extreme cold also reduces unwanted noise, making it easier to generate and control phonons with remarkable precision. Researchers observed behaviour that existing theories cannot fully explain Current scientific theories predict that sound-like vibrations should only appear under certain conditions. However, the new device produced phonons even after the electrons were pushed far beyond those predicted limits. This suggests that scientists may need to rethink some existing ideas about how energy moves through advanced quantum materials. Explaining the discovery, Michael Hilke, Associate Professor of Physics at McGill University and co-author of the study, said: Modern communication is largely based on light, including electromagnetic waves and electrical currents. In a medium such as water, sound can travel, whereas light and electrical currents cannot. In the human body, sound waves can also be a useful tool. How could this technology improve communication? Today’s communication systems mainly rely on light, radio waves, and electrical signals. However, these methods do not work equally well in every environment. For example, sound travels much more effectively underwater than light or electrical signals. If scientists can successfully develop phonon-based technologies, future communication systems could become faster, more reliable, and better suited for challenging environments. Researchers believe phonon lasers could eventually complement or even improve existing communication technologies in certain applications. Also read: Instagram runs child sexual abuse ads in India, BBC finds: IT Minister Ashwini Vaishnaw orders MeitY to seek details from tech giant

Potential medical applications
Challenges remain before real-world use Despite the breakthrough, the technology is still in its early stages. One major challenge is that the device only works at temperatures extremely close to absolute zero. Maintaining such conditions requires large and expensive cooling equipment, making practical use difficult for now. To overcome this limitation, researchers are already exploring other materials, including graphene, which may allow similar quantum effects to occur at much higher and more practical temperatures. If successful, future versions of the technology could contribute to faster communication systems, ultra-sensitive scientific instruments, next-generation medical diagnostics, and entirely new quantum devices.