Observation of Resonant Photon Blockade at Microwave Frequencies using Correlation Function Measurements

TL;DR

This paper reports the observation of photon blockade at microwave frequencies by measuring correlation functions, demonstrating antibunching in a microwave photon source using a resonator with embedded qubits.

Contribution

It presents the first experimental demonstration of photon blockade at microwave frequencies through correlation function measurements.

Findings

Observation of antibunching in microwave photons

Measurement of Mollow-triplet-like spectra

Confirmation of photon blockade phenomenon

Abstract

Creating a train of single photons and monitoring its propagation and interaction is challenging in most physical systems, as photons generally interact very weakly with other systems. However, when confining microwave frequency photons in a transmission line resonator, effective photon-photon interactions can be mediated by qubits embedded in the resonator. Here, we observe the phenomenon of photon blockade through second-order correlation function measurements. The experiments clearly demonstrate antibunching in a continuously pumped source of single microwave photons measured using microwave beam splitters, linear amplifiers, and quadrature amplitude detectors. We also investigate resonance fluorescence and Rayleigh scattering in Mollow-triplet-like spectra.