Engineering One Axis Twisting via a Dissipative Berry Phase Using Strong Symmetries.

Area of Science:

• Quantum optics
• Atomic physics
• Quantum information science

Background:

• Spin-squeezed states are crucial for enhancing measurement precision in quantum metrology.
• Generating these states often requires complex engineered dissipation or fine-tuning systems to critical points.
• Cavity-Quantum Electrodynamics (Cavity-QED) experiments typically operate in the dispersive regime with minimal optical excitation.

Purpose of the Study:

• To demonstrate a new method for dynamically generating metrologically useful spin-squeezed states.
• To explore the role of inherent symmetry in open quantum systems for quantum state generation.
• To investigate entanglement generation in the resonant regime of atom-cavity systems.

Main Methods:

• Utilizing a driven-dissipative optical cavity coupled to a collective ensemble of atoms.
• Leveraging a strong symmetry inherent in open quantum systems, particularly those with collective dissipation like superradiance.
• Exploiting the accumulation of an atom number-dependent Berry phase facilitated by this symmetry.
• Observing emergent one-axis twisting dynamics driven by the Berry phase.

Main Results:

• Dynamically generated metrologically useful spin-squeezed states without complex engineered dissipation or critical point tuning.
• Preservation of coherence due to the utilized symmetry, enabling entanglement generation.
• Successful generation of entanglement in the resonant atom-cavity regime with significant optical excitations.
• Demonstration of a pathway beyond the typical dispersive regime in cavity-QED.

Conclusions:

• Inherent symmetries in open quantum systems can be effectively utilized to generate valuable quantum states like spin-squeezed states.
• The resonant regime of atom-cavity interaction, with macroscopic optical excitations, is a viable pathway for entanglement generation.
• This work offers a simpler and potentially more robust method for creating spin-squeezed states for quantum metrology applications.