Observation of Intensity Squeezing in Resonance Fluorescence from a Solid-State Device

Area of Science:

• Quantum Optics
• Solid-State Physics

Background:

• Intensity squeezing, a reduction in photon number fluctuations below the shot-noise limit, is crucial for quantum metrology.
• Theoretical predictions of intensity squeezing in resonance fluorescence date back to 1979.
• Experimental realization in solid-state systems faced challenges due to fluorescence generation, collection, and detection inefficiencies.

Purpose of the Study:

• To experimentally demonstrate intensity squeezing in a solid-state resonance fluorescence source.
• To overcome previous experimental limitations in observing resonance fluorescence squeezing.
• To establish a new standard for optical radiation and advance scalable quantum metrology.

Main Methods:

• Utilized a single-mode fiber-coupled resonance fluorescence single-photon source based on a quantum dot-micropillar system.
• Detected pulsed single-photon streams with a system efficiency of 22.6%.
• Quantified intensity squeezing by measuring photon number fluctuations relative to the shot-noise limit.

Main Results:

• Observed intensity squeezing of 0.59 dB in the detected single-photon streams.
• Demonstrated sub-shot-noise intensity fluctuations, confirming the presence of squeezing.
• Estimated a corrected squeezing value of 3.29 dB at the first lens, indicating significant quantum enhancement.

Conclusions:

• Successfully demonstrated intensity squeezing in a solid-state resonance fluorescence system for the first time.
• The observed squeezing completes the fundamental understanding of resonance fluorescence phenomena.
• The developed source offers potential as a new standard for optical radiation and for scalable quantum metrology using indistinguishable single photons.