Fast cavity-enhanced atom detection with low noise and high fidelity

Area of Science:

• Quantum optics
• Atomic physics
• Cavity quantum electrodynamics

Background:

• Cavity quantum electrodynamics (cQED) explores light-matter interactions within optical microcavities.
• Atomic number fluctuations can exceed probe field noise in cQED experiments, complicating measurements.
• Previous methods were significantly impacted by atomic number fluctuations.

Purpose of the Study:

• To demonstrate that nonlinearities and multi-atom statistics can suppress atomic number fluctuations.
• To achieve high-fidelity, low-noise atom density measurements in cold atom clouds.
• To advance atom detection techniques in cQED.

Main Methods:

• Utilizing optical microcavities to confine cold atoms.
• Applying nonlinear optical techniques and analyzing multi-atom statistics.
• Measuring atom densities and detection fidelities over time.

Main Results:

• Atomic fluctuations were suppressed, enabling measurements near the photon shot-noise limit.
• Achieved atom densities below 1 atom per cavity mode volume.
• Demonstrated high-efficiency atom detection with fidelities >97% (10 μs) and >99.9% (30 μs).

Conclusions:

• Nonlinearities and multi-atom statistics effectively mitigate atomic number noise in cQED.
• The demonstrated technique allows for precise, low-noise measurements of cold atom densities.
• Fast and highly accurate atom detection is achievable, advancing quantum measurement capabilities.