Comparative analysis of properties for amplified coherent state and amplified squeezed vacuum

摘要

Two "amplified" quantum states, that is, amplified coherent state (ACS) and amplified squeezed vacuum (ASV), are considered in this paper by applying operator (g - 1)a dagger a + 1 on coherent state (CS) and squeezed vacuum (SV), respectively. Here g (>= 1) denotes a amplification factor and a dagger(a) denote the creation (annihilation) operator. Along these two lines, we make a comparative analysis of properties for ACS and ASV. The considered properties include density matrix elements, Wigner function, mean photon number, second-order autocorrelation function, and quadrature squeezing. We derive analytical expressions and make numerical simulations for all the properties. The noteworthy results include: (1) the ACS has antibunching and squeezing characters; (2) the ASV will have the bunching and antibunching effect in small initial squeezing.