Abstract

It is known that Alice can send an unknown quantum state |psi> to Bob with classical communication if they already share an ideal maximally entangled state. When they do not share entanglement, the best teleportation fidelity they can achieve is the classical threshold $f_c$, which varies inversely with the dimension of |psi>. We say an entangled state rho is useful for teleportation if its maximal average teleportation fidelity is strictly larger than f_c. If rho is not useful for teleportation but can be made useful after a successful local filtering operation, we say that rho has hidden teleportation power. In this talk, I will discuss two methods for determining whether an entangled state has hidden teleportation power. I will apply these methods to several families of entangled states, which include qudit Werner states. I will also describe our proof-of-principle experiment demonstrating the activation of teleportation power for a family of rank-deficient entangled two-qubit states.