In the literature on the continuous-variable bosonic teleportation protocol
due to [Braunstein and Kimble, Phys. Rev. Lett., 80(4):869, 1998], it is often
loosely stated that this protocol converges to a perfect teleportation of an
input state in the limit of ideal squeezing and ideal detection, but the exact
form of this convergence is typically not clarified. In this paper, I
explicitly clarify that the convergence is in the strong sense, and not the
uniform sense, and furthermore, that the convergence occurs for any input state
to the protocol, including the infinite-energy Basel states defined and
discussed here. I also prove, in contrast to the above result, that the
teleportation simulations of pure-loss, thermal, pure-amplifier, amplifier, and
additive-noise channels converge both strongly and uniformly to the original
channels, in the limit of ideal squeezing and detection for the simulations.
For these channels, I give explicit uniform bounds on the accuracy of their
teleportation simulations. I then extend these uniform convergence results to
particular multi-mode bosonic Gaussian channels. These convergence statements
have important implications for mathematical proofs that make use of the
teleportation simulation of bosonic Gaussian channels, some of which have to do
with bounding their non-asymptotic secret-key-agreement capacities. As a
byproduct of the discussion given here, I confirm the correctness of the proof
of such bounds from my joint work with Berta and Tomamichel from [Wilde,
Tomamichel, Berta, IEEE Trans. Inf. Theory 63(3):1792, March 2017].
Furthermore, I show that it is not necessary to invoke the energy-constrained
diamond distance in order to confirm the correctness of this proof.Comment: 19 pages, 3 figure
