Quantum frequency doubling based on tripartite entanglement with cavities

Guo Juan^{1, 2}, Wei Zhi-Feng^{1, 2}, Zhang Su-Ying^{2, †,}

Scheme for producing the tripartite entangled state of modes 1, 2, and 3 with three single squeezed states (one state is squeezed in Y direction, the other two are squeezed in X direction) and two beam splitters (one is 1:2 BS and the other is 1:1).