Quantum collective motion of macroscopic mechanical oscillators

Area of Science:

• Quantum physics
• Optomechanics
• Condensed matter physics

Background:

• Collective phenomena in complex systems exhibit unique behaviors.
• Previous studies of quantum collective phenomena in mechanical oscillators were limited by the need for identical components.

Purpose of the Study:

• To demonstrate the quantum regime for collective motion in a system of six mechanical oscillators.
• To explore the transition from individual to collective motion in an optomechanical platform.

Main Methods:

• Utilized a superconducting circuit optomechanical platform with N=6 mechanical oscillators (a hexamer).
• Increased optomechanical couplings to induce a transition from individual to collective motion.
• Employed sideband cooling to prepare the collective mode in the quantum ground state.

Main Results:

• Observed a [Formula: see text] enhancement of cavity-collective mode coupling, similar to superradiance.
• Confirmed collective motion where zero-point motion is distributed across multiple oscillators.
• Characterized the quantum ground state of the collective mode via quantum sideband asymmetry measurement.

Conclusions:

• The study successfully demonstrated the quantum regime for collective motion in a hexamer of mechanical oscillators.
• This work paves the way for investigating multipartite entanglement in macroscopic quantum systems.
• The findings hold potential for advancements in quantum metrology applications.