Self-synchronization and dissipation-induced threshold in collective atomic recoil lasing.

Area of Science:

• Atomic physics
• Quantum optics
• Nonlinear dynamics

Background:

• Globally coupled oscillators demonstrate phase transitions from incoherent to coherent states.
• Atoms within a unidirectional ring cavity form a globally coupled network.
• Collective atomic recoil lasing (CARL) facilitates coupling via cooperative Bragg scattering.

Purpose of the Study:

• To experimentally investigate the phase transition in a globally coupled atomic system.
• To understand the threshold dynamics of collective atomic recoil lasing.
• To observe synchronized atomic motion induced by CARL and friction.

Main Methods:

• Utilizing a high-finesse ring cavity with unidirectionally pumped laser.
• Inducing a self-formed atomic density grating for cooperative Bragg scattering.
• Applying an additional friction force to the atomic ensemble.
• Analyzing the threshold behavior of the lasing process.

Main Results:

• Observed a phase transition from incoherent to coherent states in the atomic network.
• Demonstrated that collective atomic recoil lasing drives synchronized atomic motion.
• Threshold analysis provided insights into the transition dynamics.

Conclusions:

• The atomic system in a ring cavity effectively models globally coupled oscillators.
• Collective atomic recoil lasing is a viable mechanism for inducing synchronized behavior.
• Experimental verification of the predicted phase transition was achieved.