Dynamic resonance fluorescence in solid-state cavity quantum electrodynamics

TL;DR

This paper reports the first observation of dynamic resonance fluorescence spectra beyond the Mollow-triplet in a solid-state cavity QED system, revealing complex spectral features and interference effects under strong, pulsed excitation.

Contribution

It provides the first experimental demonstration and systematic analysis of spectra beyond the Mollow-triplet in a solid-state system with a full quantum model including phonon effects.

Findings

Observation of up to five pairs of side peaks in the spectrum

Spectral asymmetry induced by excitation detuning

Cavity filtering effects on the resonance fluorescence

Abstract

The coherent interaction between a two-level system and electromagnetic fields serves as a foundation for fundamental quantum physics and modern photonic quantum technology. A profound example is resonance fluorescence, where the non-classical photon emission appears in the form of a Mollow-triplet when a two-level system is continuously driven by a resonant laser. Pushing resonance fluorescence from a static to dynamic regime by using short optical pulses generates on-demand emissions of highly coherent single photons. Further increasing the driving strength in the dynamical regime enables the pursuit of exotic non-classical light emission in photon number superposition, photon number entanglement, and photon bundle states. However, the long-sought-after spectrum beyond the Mollow-triplet, a characteristic of dynamic resonance fluorescence under strong driving strength, has not been observed yet. Here we report the direct observation and systematic investigations of dynamic resonance fluorescence spectra beyond the Mollow-triplet in a solid-state cavity quantum electrodynamic system. The dynamic resonance fluorescence spectra with up to five pairs of side peaks, excitation detuning induced spectral asymmetry, and cavity filtering effect are observed and quantitatively modeled by a full quantum model with phonon scattering included. Time-resolved measurements further reveal that the multiple side peaks originate from interference of the emission associated with different temporal positions of the excitation pulses. Our work facilitates the generation of a variety of exotic quantum states of light with dynamic driving of two-level systems.