Non-local effects in the resonance fluorescence from a two-level system

Yiying Yan, Zhiguo Lü, Hang Zheng

Carlos R. Stroud, H. R. Gray

L. A. Amarante Ribeiro

In this work we study the effect of thermal fluctuations in the resonance fluorescence of a two-level system. The damped two-level system is driven by a strong incident classical field near resonance frequency. To simulate the thermal bath we introduce a large system of harmonic oscillators that represent the normal modes of the thermal radiation field. To obtain the time development of the fluorescent light intensity we solve the Heisenberg equations of motion transformed in a system of coupled integral equations by an iterative method. The results show that the presence of the bath modifies dramatically the time development of the fluorescence light intensity when compared with the case T=0 K.

H. Walther

Shunfa Liu, Chris Gustin, Liu, Hanqing +7 more

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.

Serge Reynaud, Claude N. Cohen-Tannoudji