We present a study of collective multiphoton blockade in coherently driven atoms in a single-mode cavity. Considering two atoms strongly coupled to an optical cavity, we show that the two-photon blockade with two-photon antibunching, and the three-photon blockade with three-photon antibunching can be observed simultaneously. The three-photon blockade probes both dressed states in the two-photon and three-photon spaces. The two-photon and three-photon blockades strongly depend on the location of the two atoms in the strong-coupling regime. The asymmetry in the atom-cavity coupling constants opens pathways for multiphoton blockade which is also shown to be sensitive to the atomic decay and pumping strengths. The work presented here predicts many quantum statistical features due to the collective behavior of atoms and can be useful to generate nonclassical photon pairs.
We investigate theoretically the model of a cavity-quantum-electrodynamics (QED) system that consists of two two-level atoms coupled to a single-mode cavity in the weak coupling regime, where the system is driven by quantum light. The dynamics behavior of the entire system is tackled in the framework of a cascaded quantum system. We find that the two-photon blockade with two-photon bunching and three-photon antibunching can be obtained even when the strong system dissipation is included. This result shows that our work has potential for realizing entangled photon pairs in a weakly coupled cavity. Moreover, we also analyze the photon statistics of the system in the case of out-of-resonance coupling between cavity and two nonidentical atoms. Here, an unconventional photon blockade effect with suppression of two-photon correlation and enhancement of three-photon correlation can be realized, which shows many quantum statistical characteristics of a cavity QED system in weak coupling.
We propose a mechanism to engineer an
n-photon blockade in a nonlinear cavity with an
n-photon parametric drive $\ensuremath{\lambda}({\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{a}}^{\ifmmode\dagger\else\textdagger\fi{}n}+{\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{a}}^{n})$. When an
n-photon-excitation resonance condition is satisfied, the presence of
n photons in the cavity suppresses the absorption of the subsequent photons. To confirm the validity of this proposal, we study the
n-photon blockade in an atom-cavity system, a Kerr-nonlinear resonator, and two-coupled Kerr-nonlinear resonators. Our results demonstrate that
n-photon bunching and
(n+1)-photon antibunching can be simultaneously obtained in these systems. This effect is due both to the anharmonic energy ladder and to the nature of the
n-photon drive. To show the importance of the drive, we compare the results of the
n-photon drive with a coherent (one-photon) drive, proving the enhancement of antibunching in the parametric-drive case. This proposal is general and can be applied to realize the
n-photon blockade in other nonlinear systems.
We theoretically investigate the quantum-interference-induced photon blockade effect in a single two-level atom-cavity quantum electrodynamics (QED) system with degenerate parametric amplification. The analytical calculations reveal the optimal parametric gain and phase parameters for achieving optimum unconventional photon blockade conditions. Under the optimal parameter regime, the numerical results of the second-order correlation function demonstrate strong photon antibunching consistent with the analytical results. Furthermore, the numerical results corroborate that coherently driving the atom leads to a stronger photon blockade than a coherently driven cavity with the optimal parameters. We numerically demonstrate that the UPB effect is compromised by a non-zero cavity-atom coupling in the cavity-driven configuration. However, stronger photon antibunching can be attained with a non-zero cavity-atom coupling in the atom-driven configuration. This work may be suitable for experimentally realising a strongly antibunched single-photon source for applications in quantum technology.
Summary form only given. Open driven quantum systems exhibit fluctuations during their walk through Hilbert space. These can be reduced by blocking parts of the Hilbert space. For discrete variables such as particle number a blockade can result from a sufficiently strong interaction between the involved quanta, for example, the effective interaction of photons in an optically nonlinear medium.We implemented the blockade in a strongly coupled cavity quantum electrodynamics system consisting of a single two-level atom strongly coupled to a high finesse optical resonator (see Fig. 1a). This combined system exhibits a new energy structure with an anharmonic ladder of dressed states that scales with ,/n (see Fig. 1b), where n is the number of excitations. Only this special structure provides a photon-number dependent nonlinearity which is necessary to address specific manifolds with the drive.
Abstract We propose an innovative model predicated on giant atom-cavity system, wherein three cavity modes are interconnected via nearest-neighbor photon tunneling, and a giant atom is simultaneously coupled with two single-mode cavities on each side. This model demonstrates both photon blockade and photon bunching effects simultaneously. Specifically, when the giant atom is weakly driven, the central cavity displays unconventional photon blockade with g b ( 2 ) ( 0 ) ≈ 1 0 − 5.97 , while the side cavities exhibit photon bunching effects with g a ( 2 ) ( 0 ) = g c ( 2 ) ( 0 ) ≈ 1 0 4.85 due to the quantum interference and the anharmonicity of energy eigenvalues. This model introduces a fresh perspective for investigating intricate photon behaviors in multi-cavity systems.