Light Scattering from Solid-State Quantum Emitters: Beyond the Atomic Picture

Abstract

Coherent scattering of light by a single quantum emitter is a fundamental process at the heart of many proposed quantum technologies. Unlike atomic systems, solid-state emitters couple to their host lattice by phonons. Using a quantum dot in an optical nanocavity, we resolve these interactions in both time and frequency domains, going beyond the atomic picture to develop a comprehensive model of light scattering from solid-state emitters. We find that even in the presence of a cavity, phonon coupling leads to a sideband that is completely insensitive to excitation conditions, and to a non-monotonic relationship between laser detuning and coherent fraction, both major deviations from atom-like behaviour. arXiv:1904.05284v2 [quant-ph]We model a quantum dot (QD) as a two level system (TLS) with ground state |0 and a single exciton state |X , with splitting ω X ( = 1). The QD is driven by a continuous wave laser with a frequency ω L and Rabi coupling Ω. The QD couples to both a vibrational environment and a low-Q optical cavity, which is characterised by the Hamiltonian [41]:

Molecule-photon interactions in phononic environments

“…6(a) and 6(b), we plot the cavity transmission at resonance ω c = ω for increasing thermal occupation with and without the influence of phonons and find that the splitting of the polariton modes is well described by Eq. (35). This also manifests itself in the transmission signal in the Purcell 1, which is a more realistic regime in currently available single-molecule experiments [12,16].…”

“…However, it should also be borne in mind that the relevance of our treatment is not restricted to the physical system considered here as very similar effects also occur in related solid-state emitters such as quantum dots or vacancy centers in diamond. The coupling of such systems to photonic nanostructures has been studied quite extensively over the last years [29][30][31][32][33][34][35][36]. There is, furthermore, a general current interest in impurities interacting with a quantum many-body environment, such as molecular rotors immersed in liquid solvents [37,38], Rydberg impurities in quantum gases [39] or magnetic polarons in the Fermi-Hubbard model [40].…”

Phonon effects in quantum dot single-photon sources

“…Recent studies investigate the dynamics and limitations of the optical excitation process [10] and demonstrate how the phonon sideband can be used to increase the pumping efficiency without sacrificing the photon indistinguishability [11]. Other recent investigations focus on the properties of light scattered from a solid-state quantum emitter [81,82]. Furthermore, a larger parameter space and a range of new phenomena arise when the Fabry-Perot cavity is replaced with a non-Lorenzian cavity, which opens up a rich class of dynamics [83,84].…”

Photon Statistics of Filtered Resonance Fluorescence

“…These contributions destructively interfere to give zero when no filters are present, and this interference is partially or completely removed when filters are introduced. It is interesting to note that, when moving from Γ ¼ 150 γ to Γ ¼ 23 γ, nearly the entire phonon sideband [25,26,34] is removed with no appreciable change in g ð2Þ ð0Þ. The nature of these measurements mean that electron-phonon interaction processes such as excitation-induced dephasing [27] and phonon sideband emission [25,26,34] have negligible impact on g ð2Þ ðtÞ.…”