Quantum entanglement of particles is now an established technology. It takes two or more unmeasured particles and correlates them in such a way that their properties become blurs and mirrors of one another. One measurement and the corresponding properties of the other are instantly locked in place, even when separated by a distance.
In new research, physicists theorize a bold way to change this by entangling two very different types of particles – units of light, or photons – with phonons, the quantum equivalent of sound waves.
Physicists Changlong Zhu, Claudiu Genes and Birgit Stiller from the Max Planck Institute for the Science of Light in Germany called the new system they proposed photoacoustic entanglement.
This represents a hybrid system using two very different fundamental particles and is an important step toward more robust quantum devices by establishing a form of entanglement that is uniquely resistant to external noise, one of the biggest challenges facing quantum technology.
Quantum entanglement has promising applications for high-speed quantum communications and quantum computing. The unique physics of defining isolated and entangled particles before and after measurement makes them ideal for a variety of applications, from cryptography to high-speed algorithms.
However, the delicate quantum states required for these processes can be easily broken, a problem that hinders their realization in practical applications.
Scientists are working to solve this problem through several promising routes. higher dimension Reduces the impact of degrading noise. Add more particles In a tangled system. However, it is very likely that a viable solution will involve more than one path, so the more options you have, the more likely you are to find the right combination.
The route Zhu and his colleagues investigated involves pairing a photon not with another photon, but with a completely different ‘particle’ of radio waves: sound. This is very difficult to achieve because photons and phonons travel at different speeds and have different energy levels.
The researchers used a process called Brillouin scattering to show how particles can become entangled. This process causes light to be scattered by waves of heat-generated sound vibrations between the atoms of the material.
In the proposed solid-state system, the researchers pulse laser light and sound waves into an on-chip solid-state Brillouin active waveguide designed to induce Brillouin scattering. When two protons travel along the same photon structure, phonons travel at much slower speeds, resulting in scattering that can entangle particles carrying dramatically different energy levels.
What makes this even more exciting is that it can be achieved at higher temperatures than standard entanglement approaches, bringing entanglement into the cryogenic region and potentially reducing the need for expensive specialized equipment.
Although further investigation and testing is needed, the results are promising, the researchers say.
“The fact that the system operates over a wide bandwidth in both optical and acoustic modes.” they write“It opens a new perspective on entanglement as a continuum mode with great potential for applications in quantum computation, quantum storage, quantum metrology, quantum teleportation, entanglement-assisted quantum communication and boundary exploration. Between the classical world and the quantum world.”
This study was published in: actual review letter.
