Abstract Recently, a groundbreaking advancement known as multimode photon blockade (MPB) is proposed by S. Chakram et al. [Nature. Phys. 18, 879‐884 (2022)], showcasing its ability to generate multimode W states. Inspired by their work, in this paper, an interesting method is proposed to investigate MPB by engineering the eigenstates of the system Hamiltonian, which is defined as the reverse design method. It is demonstrated that an entangled state is created with a certain probability by sharing a single photon between two coupled Kerr‐nonlinear cavities. This entangled state in the two‐coupled cavities blocks the creation of the subsequent photons. The system is in a superposition of only the entangled state and the vacuum state. And the photon blockade (PB) exists in two cavities simultaneously. The reversed design method can also be utilized to study MPB in three coupled cavities with Kerr nonlinearities by creating a three‐qubit W state.
The photon blockade phenomenon, a promising tool for realizing efficient single-photon sources, is the central focus of our work. We study this phenomenon within the context of the multimode extension of the Jaynes-Cummings model, incorporating two-photon dissipation and external coherent driving. Operating in the weak-driving regime, we confine our analysis to the two-excitation sector of the Hilbert space, initially exploring the single-mode case and then focusing on the corresponding multimode problem. Our study calculates the second-order correlation function (both numerically and analytically) for zero- and nonzero time delays in single- and multimode cases, to pinpoint and validate the conditions that lead to conventional and unconventional photon blockade. Our zero delay findings reveal that photon antibunching is comparable in both cases; however, the multimode case offers a greater degree of control and applicability. Furthermore, for non-zero delay operation, we find that when one of the multiple modes is set at the optimal conventional photon blockade conditions, the behavior of the curve mimics the single-mode problem with an overall slower rate of reaching the
g(2)(τ)=1 value. These results highlight the practical implications of our findings for building useful single-photon sources.
We present a geometric interpretation of the sum photon blockade effect in multimode quantum optical systems, such as semiconductor microresonators. The blockade condition
c(n)⋅v=0 reflects the orthogonality of the
n-photon amplitude vector to a target mode vector in an
N-dimensional Hilbert space, visualized as the confinement of the state to a hyperplane.
A key result is the calculation of the maximum probability of the system remaining in the blockade subspace under the influence of decoherence processes (in particular, dephasing), which determines the practical feasibility and robustness of the effect. This approach extends to higher-order correlators
gΣ(2) and cross-correlations, enabling the design of scalable quantum devices.
We introduce the concept of "dark-state typicality": as the number of modes
M increases, the dark subspace annihilated by the collective mode operator asymptotically occupies a unit fraction of the
n-boson Hilbert space. This allows the transition from fragile, finely tuned mechanisms to macroscopically robust non-classical light in large multimode bosonic architectures.
We consider continuum collective modes, hypotheses on correlation zeros and invariant manifolds, as well as the relationship between blockade and entanglement.