Photon Statistics of Propagating Thermal Microwaves

Area of Science:

• Quantum optics
• Superconducting quantum circuits
• Quantum information science

Background:

• Characterizing photon statistics is crucial for quantum circuit experiments.
• Understanding microwave fields is essential for quantum technologies.
• Thermal photon emissions require precise measurement techniques.

Purpose of the Study:

• To quantify the photon number variance of thermal microwave photons.
• To characterize weak microwave states using experimental methods.
• To investigate noise properties of Josephson parametric amplifiers.

Main Methods:

• Experiments utilizing superconducting quantum circuits.
• Employing correlation measurements to probe microwave fields.
• Using a transmon qubit coupled to a microwave resonator for field analysis.

Main Results:

• Quantified the n²+n photon number variance for thermal microwave photons.
• Measured mean photon numbers in the range of 0.05 to 1.5.
• Provided a precise characterization of weak microwave states.

Conclusions:

• The study offers a quantitative understanding of thermal microwave photon statistics.
• Experimental results yield insights into noise characteristics of Josephson parametric amplifiers.
• This work advances the characterization of quantum states in microwave fields.