Improvement of entanglement via quantum scissors

We propose a theoretical scheme for entanglement distillation of the two-mode squeezed vacuum state (TMSVS) by nondeterministic optical nonlinear amplification based on the work of Anisimov et al. [Phys. Rev. Lett. 104, 103602 (2010)]. By applying the quantum-scissors operations to both modes of the TMSVS, only the twin vacuum and the twin one-photon components can survive in the resulting state. We show that both entanglement and squeezing can be enhanced in the high-transmissivity and low-squeezing region. In addition, a comparison with symmetrical single-photon subtraction and quantum catalysis shows that the proposed states can achieve a better entanglement enhancement than the photon subtraction in a high-transmissivity region, and a similar property is shared by the catalyzed states in low-transmissivity regions. (C) 2017 Optical Society of America