  We investigate the nonclassicality of several kinds of nonclassical optical
fields such as the pure or mixed single photon-added coherent states and the
cat states in the photon-loss or the dephasing channels by exploring the
entanglement potential as the measure. It is shown that the long-time decay of
entanglement potentials of these states in photon loss channel is dependent of
their initial quadrature squeezing properties. In the case of photon-loss,
transition of long-time decay rate emerges at the boundary between the
squeezing and non-squeezing initial non-gaussian states if log-negativity is
adopted as the measure of entanglement potential. However, the transition
behavior disappears if the concurrence is adopted as the measure of
entanglement potential. For the case of the dephasing, distinct decay behaviors
of the nonclassicality are also revealed.
