Two-mode quantum systems: Invariant classification of squeezing transformations and squeezed states
Two-mode quantum systems: Invariant classification of squeezing transformations and squeezed states
A general anaylsis of squeezing transformations for two-mode systems is given based on the four-dimensional real symplectic group Sp(4,openR). Within the framework of the unitary (metaplectic) representation of this group, a distinction between compact photon-number-conserving and noncompact photon-number-nonconserving squeezing transformations is made. We exploit the U(2) invariant squeezing criterion to …