Scientists have made breakthrough progress in using laser to cool sound waves

A group of researchers from the Max Planck Institute of Optoelectronics has made a significant breakthrough in using laser cooling to travel sound waves. This development brings us one step closer to the quantum ground state of sound in waveguides, which is of great significance for quantum communication systems and future quantum technology.

By using laser cooling, scientists can significantly reduce the temperature of sound waves in optical fibers. They achieved a significant reduction of 219K, ten times higher than previously reported. In the end, they managed to reduce the initial number of phonons by 75% at a temperature of 74 K.

The key to this success lies in utilizing stimulated Brillouin scattering, a nonlinear optical effect that can effectively couple light waves to sound waves. Laser is used to cool acoustic vibrations, creating an environment with minimal thermal noise. This decrease in temperature has a significant impact on quantum systems, as thermal noise can hinder the functionality of quantum communication systems.

A significant advantage of using glass fibers is that they can conduct light and sound over long distances while maintaining strong interactions. During the experiment, researchers used a 50 centimeter long optical fiber to cool the sound wave that extended its entire length. Considering that most of the platforms previously brought to the quantum ground state were microscopic in size, this is remarkable.

The realization of cooling sound waves to such low temperatures has opened up new experimental fields, allowing for a deeper understanding of the fundamental properties of matter. In addition, due to the broadband and continuous existence of sound waves in waveguide systems, these advancements are of great significance for high-speed communication systems.

"We are very enthusiastic about the new insights that pushing these fibers into quantum ground states will bring," said Dr. Birgit Stiller, head of the Quantum Photoacoustics group. Not only from the perspective of basic research, it enables us to glimpse the quantum properties of extended objects, but also because it may have applications in quantum communication schemes and future quantum technologies.

In summary, the breakthrough made by researchers at the Max Planck Institute in utilizing laser cooling of sound waves has brought us closer to achieving the quantum ground state of sound. This development is of great significance to quantum communication systems and opens up new possibilities for future quantum technology.

Source: Laser Net