Conditional quantum-state engineering using ancillary squeezed-vacuum   states
  We investigate an optical scheme to conditionally engineer quantum states using a beam splitter, homodyne detection and a squeezed vacuum as an ancillar state. This scheme is efficient in producing non-Gaussian quantum states such as squeezed single photons and superpositions of coherent states (SCSs). We show that a SCS with well defined parity and high fidelity can be generated from a Fock state of $n\leq4$, and conjecture that this can be generalized for an arbitrary $n$ Fock state. We describe our experimental demonstration of this scheme using coherent input states and measuring experimental fidelities that are only achievable using quantum resources. 
Hyunseok Jeong, Andrew M. Lance, Nicolai B. Grosse, Thomas Symul, Ping   Koy Lam, and Timothy C. Ralph