  How to prepare deterministically non-Gaussian entangled states is a
fundamental question for continuous-variable quantum information technology.
Here, we theoretically demonstrate through numerical methods that the
triple-photon state generated by three-photon spontaneous parametric
down-conversion is a pure super-Gaussian resource of non-Gaussian entanglement.
Interestingly, the degree of entanglement between the modes of the
triple-photon state is stronger than that corresponding to the two-mode
squeezed vacuum state produced by a quadratic Hamiltonian with the same
parameters. Furthermore, we propose a model to prepare two-mode non-Gaussian
entangled states with tunable non-Gaussianity based on quadrature projection
measurements.
