Scientists at EPFL have achieved a significant breakthrough in quantum physics by successfully synchronizing six mechanical oscillators into a collective quantum state. This achievement represents a major step forward in the field of quantum technologies.
Mechanical oscillators, which are already used in everyday devices like quartz watches and mobile phones, have potential applications in quantum computing and sensing. However, controlling multiple oscillators at the quantum level has been challenging because it requires nearly identical units with exceptional precision.
Led by Tobias Kippenberg, the research team managed to overcome these challenges through a superconducting platform that achieved extremely low disorder among mechanical frequencies, with variations as small as 0.1%. This precision was crucial for enabling the oscillators to enter a collective state where they function as a unified system rather than independent components.
The team employed a technique called sideband cooling to observe quantum effects. This process involves using a precisely tuned laser to reduce the oscillators’ energy to their quantum ground state – the lowest energy level possible under quantum mechanics. By increasing the coupling between the microwave cavity and the oscillators, the researchers observed the system transition from individual to collective dynamics.
A key finding was the observation of quantum sideband asymmetry across the entire system of oscillators, demonstrating collective quantum motion rather than quantum behavior limited to a single object. The researchers also noted enhanced cooling rates and the emergence of “dark” mechanical modes – modes that didn’t interact with the system’s cavity and maintained higher energy levels.
This breakthrough has significant implications for quantum technologies. The ability to control collective quantum motion in mechanical systems could lead to advances in quantum sensing and the generation of multi-partite entanglement. It also provides experimental confirmation of theoretical predictions about collective quantum behavior in mechanical systems.
The research, published in Science, marks an important milestone in developing large-scale quantum systems. The team’s success in managing multiple oscillators at the quantum level opens new possibilities for exploring quantum states and developing more powerful quantum systems. This advancement could contribute to innovations across multiple industries, particularly in the fields of ultra-sensitive sensors and quantum computing components.
Reference: “Quantum collective motion of macroscopic mechanical oscillators” by Mahdi Chegnizadeh, Marco Scigliuzzo, Amir Youssefi, Shingo Kono, Evgenii Guzovskii and Tobias J. Kippenberg, 19 December 2024, Science. DOI: 10.1126/science.adr8187
