  Enhancing quantum entanglement is important for many quantum information
processing applications. In this paper, we consider a protocol for entanglement
enhancing in a two-mode squeezed vacuum state (TMSVS), attained based on photon
subtraction, photon catalysis, and photon addition. Central to such an
operation is the task of mixing and detecting number states with each mode of
TMSVS. We analyze various settings and find an optimal setup for improving the
entanglement of the state.

Quantum Physics