Vortex states for the quantized radiation field

We study the properties of wave-packet states with vortex structure. In particular we present the characteristics of a two-mode radiation field characterized by a configuration-space wave function ${\psi }_v=(x-{iy)}^m{e}^{-{(x}^2{+y}^2)/2\mathrm{}{\sigma }^2}.$ We show the generation of such states by the interaction of Λ systems with squeezed radiation in a two-mode cavity. The two modes are correlated due to entanglement, which also produces the mixed state of each mode even though the state of the two-mode field is a pure state.