Long-Lived Squeezed Ground States in a Quantum Spin Ensemble

Area of Science:

• Atomic, Molecular, and Optical Physics
• Quantum Many-Body Physics
• Quantum Information Science

Background:

• Generating non-classical states of matter is crucial for quantum technologies.
• Atomic Bose-Einstein condensates (BECs) are promising platforms for quantum state preparation.
• Previous methods often involved dynamic processes like quenching through quantum phase transitions.

Purpose of the Study:

• To generate time-stationary spin squeezed ground states in a spin-1 Bose-Einstein condensate.
• To explore a novel nonadiabatic technique for preparing these states near a quantum-critical point.
• To characterize the squeezing properties and long-term stability of the generated states.

Main Methods:

• Utilized a novel nonadiabatic technique to tune an atomic spin-1 Bose-Einstein condensate near its quantum-critical point.
• Prepared spin squeezed ground states that are time stationary.
• Measured the degree of squeezing and its evolution over time.

Main Results:

• Successfully generated spin squeezed ground states with 6-8 dB of squeezing.
• Demonstrated a constant quadrature squeezing angle for these stationary states.
• Observed a gradual decrease in squeezing over 2 seconds, attributed to Hamiltonian tuning from atomic density loss, without requiring additional decoherence models.

Conclusions:

• The novel nonadiabatic technique provides a robust method for creating stable spin squeezed ground states.
• These states exhibit remarkable resilience to decoherence, as evidenced by the modeling of their decay.
• The findings pave the way for enhanced precision measurements and quantum information processing using atomic BECs.