Enhancing quantum entanglement with the local displacement-based quantum scissor

Abstract

Entangled quantum states serve as a pivotal resource in quantum information processing, where the preparation of highly entangled quantum states is a core issue. In this paper, we propose a local displacement-based quantum scissor (LDQS) scheme to enhance the entanglement of the two-mode squeezed vacuum (TMSV) state. By introducing a local displacement operation in the traditional quantum scissor, the entanglement of the TMSV state is enhanced by approximately $75\text{\%}$ for low initial squeezing ($r=0.2$) conditions. Compared with the local squeezing-based quantum scissor scheme (Liu et al., 2022), the LDQS scheme eliminates the need for additional pumping and the use of inefficient nonlinear crystals, thereby simplifying the experimental procedure. Moreover, the LDQS scheme provides a greater enhancement in entanglement when both schemes are implemented with the same success probability. Finally, we also demonstrate that the LDQS operation can be used to enhance the entanglement of the TMSV state in lossy channels. These advantages suggest that our scheme shows promise for application in various quantum information tasks, including quantum metrology and quantum communication.