Sub-Poissonian photon statistics in quantum dot-metal nanoparticles hybrid system with gain media

Yujing Wang,Han Ye,Zhongyuan Yu,Yumin Liu,Wenbin Xu

doi:10.1038/s41598-019-46576-z

Yujing Wang, Han Ye + Show 3 more

Open Access

https://doi.org/10.1038/s41598-019-46576-z

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Abstract

In this paper, we theoretically demonstrate the sub-Poissonian photon statistics in gain-assisted quantum dot-metal nanoparticles (QD-MNPs) hybrid system with nanoscale footprint. The gain media is introduced to reduce the dissipation of localized surface plasmons and consequently the quality factor of MNPs is improved by adjusting the gain coefficient. Simulated by finite element method (FEM), the Fano resonance is observed in the absorption cross section spectrum of the hybrid system. Considering MNPs and gain media together as a single mode cavity, the system is investigated within the framework of cavity quantum electrodynamics by fitting necessary parameters with FEM. The numerical results show that the coupling between QD and MNPs falls in strong coupling regime and zero delay second-order autocorrelation function g2(0) = 0.356 can be achieved with proper choice of gain coefficient. Moreover, the sub-Poissonian photon statistics can be maintained in a large variation range of gain coefficient and a certain degree of detuning between QD and cavity is allowed.

Highlights

Solid-state single photon source (SPS) is a key component in the quantum computation[1] and quantum communication systems[2]
Considering metal nanoparticles (MNPs) and gain media together as an equivalent cavity, we calculate the zero delay second-order correlation function g2(0) and intra-cavity photon number N using cavity quantum electrodynamics[30], based on the quantum parameters fitted from the absorption cross section spectra simulated by finite element method (FEM)
Gain coefficient k = 0.086 is taken as an exemplary case to demonstrate the photon statistical properties in the proposed hybrid system

Summary

Structure and Theory

In FEM, the dielectric constant of gold semi-ellipsoids is described by Drude model, which is commonly used when simulating the optical response of plasmonic resonant MNPs33 and has the function of s(ω). The absorption cross section spectra have been demonstrated as a bridge with good consistency between discrete dipole approximation, semi-classical model and cQED, when treating the coupling between QD and MNPs22. Following this idea, we determine the eight unknown parameters in Hamiltonian and Lindblad superoperator by fitting the spectra obtained from cQED and FEM. The thermal noises induced by gain media are not taken into consideration under cold reservoir limit in present work for simplicity[30]

Results and Discussion

Conclusions

Additional Information