Parametric Amplification and Noise Squeezing in Room Temperature Atomic Vapors

Area of Science:

• Atomic physics
• Quantum optics
• Condensed matter physics

Background:

• Atomic vapors are sensitive probes of fundamental physics.
• Coherent manipulation of spin states is crucial for quantum technologies.
• Parametric processes are known in mechanical and optical systems.

Purpose of the Study:

• To demonstrate parametric excitation for coherent spin manipulation in atomic vapors at room temperature.
• To investigate the signatures and effects of parametric excitation on spin evolution.
• To assess the impact of this technique on atomic magnetometry.

Main Methods:

• Utilizing parametric excitation via periodic modulation of a pumping beam (Bell-Bloom-like technique).
• Detecting signatures in ground-state spin evolution, including excitation spectra and signal quadrature properties.
• Analyzing noise distributions and signal-to-noise ratios.

Main Results:

• Observed resonances in atomic coherences characteristic of the parametric process.
• Demonstrated amplification and attenuation of signal quadratures with asymmetric noise distributions.
• Achieved noise squeezing enhancing signal-to-noise ratio by up to a factor of 10.
• Improved Bell-Bloom magnetometer performance by a factor of 3.

Conclusions:

• Parametric excitation provides a robust method for coherent spin manipulation in atomic vapors.
• The technique offers significant noise reduction and signal enhancement for sensitive measurements.
• This approach has direct applications in advancing atomic magnetometry and related quantum sensing technologies.