Phonon laser in an optomechanical system with nonreciprocal coupling

Area of Science:

• Optomechanics
• Non-Hermitian Physics
• Quantum Optics

Background:

• Phonon lasers, analogous to optical lasers, are crucial in various research fields.
• Optomechanical systems offer a platform for studying phonon lasing dynamics.

Purpose of the Study:

• To propose and analyze a novel phonon laser based on a three-cavity optomechanical system.
• To investigate the effects of tunable nonreciprocal coupling on phonon laser properties.

Main Methods:

• Adiabatic elimination of a dissipative cavity to derive an effective non-Hermitian dual-cavity model.
• Introduction of a supermode orthogonalization method based on coupling strength weighting.
• Numerical simulations to analyze phonon lasing dynamics.

Main Results:

• Tunable nonreciprocal coupling significantly modifies phonon laser thresholds and mechanical gain.
• A novel supermode orthogonalization method is introduced for non-Hermitian systems.
• Phonon lasing dynamics are tunable due to photon population asymmetry from supermode symmetry breaking.

Conclusions:

• The proposed system offers a new paradigm for exploring phonon laser effects in non-Hermitian open systems.
• This work provides an innovative platform for integrating optomechanics with non-Hermitian photonics theory.