  We propose a scheme for generating the superposition and the entanglement of
squeezed vacuum states of electromagnetical fields. The scheme involves
single-photon source, single photon detector, and cross Kerr nonlinearity. The
Kerr nonlinearity required for generating the superposition of squeezed vacuum
states is 1/2 of that required for generating the superposition of coherent
states. The proposal can also be extended to generate the entanglement states
between two coherent states and that between one coherent state and one
squeezed vacuum state.
