Synchronization of spin-driven limit cycle oscillators optically levitated in vacuum

Area of Science:

• Quantum optics
• Optomechanics
• Non-Hermitian physics

Background:

• Opto-mechanical oscillators are systems where light and mechanical motion interact.
• Non-Hermitian systems exhibit unique properties not found in their Hermitian counterparts.
• Stochastic forces can influence the behavior of micro-scale systems.

Purpose of the Study:

• To investigate the emergence of synchronized oscillations in a pair of non-Hermitian, stochastic, opto-mechanical oscillators.
• To explore the transition from weakly correlated motion to collective, synchronized behavior.
• To identify potential applications in topological materials and quantum sensing.

Main Methods:

• Experimental setup using levitated polystyrene microspheres in laser beams.
• Theoretical analysis of non-conservative forces and optical spin.
• Observation of particle motion and correlation at varying laser powers.

Main Results:

• Particles exhibited orbital circulation and correlated stochastic motion with increasing laser power.
• A collective Hopf bifurcation was observed, leading to synchronized limit cycles.
• Synchronization was driven by weak optical and hydrodynamic interactions.

Conclusions:

• Levitated non-Hermitian opto-mechanical oscillators can achieve coherent coupled oscillations and synchronization.
• This system offers a platform for exploring opto-mechanical topological materials and classical time crystals.
• Synchronized states in levitated optomechanics could enable robust sensors and macroscopic entanglement.