ABSTRACT:
We show how the partial entanglement inherent in a two-mode squeezed
vacuum state admits two different teleportation protocols. These two
protocols refer to the different kinds of joint measurements that may be
made by the sender. One protocol is the recently implemented quadrature
phase approach of Braunstein and Kimble [Phys. Rev. Lett. **80**, 869
(1998)]. The other is based on recognizing that a two-mode squeezed vacuum
state is also entangled with respect to photon-number difference and phase
sum. We show that this protocol can also realize teleportation; however,
limitations can arise due to the fact that the photon-number spectrum is
bounded from below by zero. Our examples show that *a given entanglement
resource may admit more than a single teleportation protocol and the
question then arises as to what is the optimum protocol in the general
case*.