Entanglement and Photon Anti-Bunching in Coupled Non-Degenerate Parametric Oscillators

Abstract

We analytically and numerically show that the Hillery-Zubairy’s entanglement criterion is satisfied both below and above the threshold of coupled non-degenerate optical parametric oscillators (NOPOs) with strong nonlinear gain saturation and dissipative linear coupling. We investigated two cases: for large pump mode dissipation, below-threshold entanglement is possible only when the parametric interaction has an enough detuning among the signal, idler, and pump photon modes. On the other hand, for a large dissipative coupling, below-threshold entanglement is possible even when there is no detuning in the parametric interaction. In both cases, a non-Gaussian state entanglement criterion is satisfied even at the threshold. Recent progress in nano-photonic devices might make it possible to experimentally demonstrate this phase transition in a coherent XY machine with quantum correlations.

Photon antibunching in sixth harmonic generation

“…As stated by Gupta et al [33] in detail, higher-order antibunching is not an unusual phenomenon; rather, it can be observed in numerous simple nonlinear optical processes, such as the six-wave mixing process, the four-wave mixing process, and the second harmonic generation. Antibunching occurs in pump modes, which lose energy, whereas bunching manifests in harmonic modes, which gain energy from the pump, and vice versa: as energy decreases, noise increases [34][35][36]. All the models studied here are experimentally realizable [37,38], and the criteria for higher-order antibunching appear in terms of the factorial moment, which can be measured using homodyne photon counting experiments [37][38][39][40].…”

Analog Photonics Computing for Information Processing, Inference, and Optimization

“…optimum solution while going above the threshold of a particular Ising problem. [114,115] The main difference between the classical description of CIM (which is debated to be essentially nonclassical [146,147] ) and Hopfield NN is the additional pumping term p and saturation mechanism −x 2 i . The middle part of the Figure 8 contains simulated bifurcation machine (SBM) equations, which are inspired by the adiabatic evolution of classical nonlinear Hamiltonian systems exhibiting bifurcation phenomena.…”

“…CIM is a network of OPOs, in which the “strongest” collective mode of oscillations corresponds to an optimum solution while going above the threshold of a particular Ising problem. [ 114,115 ] The main difference between the classical description of CIM (which is debated to be essentially non‐classical [ 146,147 ] ) and Hopfield NN is the additional pumping term p and saturation mechanism $$-x_i^{2}$$.…”