  The maximum amount of entanglement achievable under passive transformations
by continuous-variable states is called the entanglement potential. Recent work
has demonstrated that the entanglement potential is upper-bounded by a simple
function of the squeezing of formation, and that certain classes of two-mode
Gaussian states can indeed saturate this bound, though saturability in the
general case remains an open problem. In this study, we introduce a larger
class of states that we prove saturates the bound, and we conjecture that all
two-mode Gaussian states can be passively transformed into this class, meaning
that for all two-mode Gaussian states, entanglement potential is equivalent to
squeezing of formation. We provide an explicit algorithm for the passive
transformations and perform extensive numerical testing of our claim, which
seeks to unite the resource theories of two characteristic quantum properties
of continuous-variable systems.
