Experimental schemes to observe the effect of unconventional photon blockade are discussed. The mechanism can be explored to optimize the performance of single-photon sources or, more generally speaking, as a tool to reveal nonclassical features.
Abstract Unconventional photon blockade (UPB) is an important quantum phenomenon that relies on the quantum interference effect. Here, we propose coupling an optical parametric amplifier (OPA) to a Kerr nonlinear single-mode cavity in a two-photon dissipation environment, enabling strong photon antibunching based on the UPB mechanism. The optimal conditions for achieving UPB are first derived analytically. The results are subsequently compared with the second-order correlation function derived from numerical simulations, and excellent agreement is observed. The findings show that UPB is enhanced without significantly reducing the mean photon number. This further demonstrates that the width of the UPB occurrence window increases with increasing OPA coefficient and driving laser intensity. Finally, theoretical analysis reveals the physical mechanism of UPB, showing that the Kerr medium is not the dominant factor for UPB generation in this system. Thus, our work offers valuable theoretical guidance for precisely controlling UPB and optimizing single-photon source performance.
We propose a hybrid cavity-magnon system scheme that integrates a yttrium iron garnet sphere with a microwave cavity filled with Kerr medium, aiming to achieve both conventional and unconventional photon blockade simultaneously. Our research demonstrates that by tuning the strength of the Kerr nonlinearity and adjusting the two-photon driving intensity, we can realize quantum effects associated with both types of photon blockade. Furthermore, through careful selection of system parameters, we have obtained optimal results for photon blockade under ideal conditions. This scheme fully exploits the advantages offered by both conventional and unconventional photon blockade mechanisms, effectively reducing the equal-time second-order photon correlation function while also achieving a higher mean photon number. It provides an alternative and experimentally feasible platform for preparing single-photon sources characterized by enhanced purity and brightness.
In this paper, we study the unconventional photon blockade of symmetric and antisymmetric modes in a photonic molecule system with bilateral drive. We show that the photon blockade effect is controllable by manipulating the tunnelling strength of two cavities and the ratio of driving strengths. Under the weak driving condition, we present the exact optimal conditions for strong antibunching photons. The optimal conditions are in good agreement with the numerical results. It is also found that the optimal value of detuning frequencies is not sensitive to the value of the ratio to achieve the unconventional photon blockade effect. The feasibility of tunable unconventional photon blockade effect also has been studied based on the experimental parameters. Our studies of the photonic molecule system can be used as a single-photon source based on the symmetric and antisymmetric modes in the regime of weak nonlinearity.