gae spedalieri

gae spedalierigae-spedalieri

Mar 23 2017 09:23 UTC
Mar 13 2017 14:13 UTC

1) Sorry but this is false.

1a) That analysis is specifically for reducing QECC protocol to an entanglement distillation protocol over certain class of discrete variable channels. Exactly as in BDSW96. Task of the protocol is changed in the reduction.

1b) The simulation is not via a general LOCC but relies on teleportation (this is why you reduce the channel to the Choi matrix of the same channel)

1c) It does not apply to CV and asymptotic simulations (even with DV channels, see amplitude damping channel in PLOB15)

2) The result for discrete-variable covariant channels is prior to WTB17, due to Matthews and Leung [IEEE Trans. Inf. Theory 61, 4486 (2015)] not cited here.
For asymptotic simulations, both WTB17 and Wolf's notes cannot apply since there is no control whatsoever of the channel simulation due to the truncation of the Hilbert space.

3a) TW16, i.e., https://arxiv.org/abs/1611.09165 is just a trivial consequence of PRL 118, 100502 (2017), i.e., https://arxiv.org/abs/1609.02160 and PRL 113, 250801 (2014), i.e., https://arxiv.org/abs/1407.2934. TW16 use exactly the same methods, while trying to come up with different names. I mean for both DV and CV channels, i.e., including bosonic channels. All is included already in those two PRLs above.

3b) Here this specific paper on quantum reading considers adaptive channel discrimination in *discrete-variables*. The ultimate limits and teleportation methods were fully worked out in PRL 118, 100502 (2017), i.e., https://arxiv.org/abs/1609.02160v1. This is not even cited here. Why?

Sorry if I cannot be more positive but you should really try to give the right credit to previous literature while avoiding self-referencing as much as possible.

Mar 13 2017 09:01 UTC
Mar 13 2017 09:01 UTC
Mar 13 2017 08:56 UTC

This is one of those papers where the contribution of previous literature is omitted and not fairly represented.

1- the LOCC simulation of quantum channels (not necessarily teleportation based) and the corresponding general reduction of adaptive protocols was developed in PLOB15 (https://arxiv.org/abs/1510.08863) not in BDSW96 or MH12 that only contained partial results. Both definition 2 and the reduction in proposition 2 of this Wilde's paper are heavily based on PLOB15 which is not credited here. On the actual status on channel simulation and reduction of adaptive protocols, see Supplementary Notes 8 and 9 in PLOB15 (https://arxiv.org/abs/1510.08863)

2- the statement that covariant channel implies teleportation simulability (Lemma 3) is also directly taken from previous papers, not Wilde's paper WTB17 (again the most general formulation of this statement was made at any dimension in PLOB15, again not credited here). Proposition 1 is another trivial consequence of PLOB15.

3- the simplification of adaptive channel discrimination via teleportation was first proven in Pirandola and Lupo PRL 118, 100502 (2017) on adaptive quantum metrology and channel discrimination, but again Wilde prefers to omit relevant literature to cite his followup paper TW16. The latter paper itself (TW16) is also based on the PRL above and a previous PRL by Lorenzo Maccone

Mar 10 2017 16:35 UTC
Mar 09 2017 09:30 UTC
Mar 09 2017 09:30 UTC
Mar 09 2017 09:29 UTC
May 03 2016 15:33 UTC

This is a nice result!

May 03 2016 15:30 UTC

From the introduction of this paper by Namiki et al.:
"Pirandola, Laurenza, Ottaviani, and Banchi (PLOB) have claimed that the corresponding tight bound is given by [8, 9] -log(1-\eta)"

Am I reading well?

1-- Do they use "claimed" instead of "proven"?

2-- Does the first author cite himself (Ref. [9]) for the results in PLOB?

As I already commented before, Ref. [9] does not add anything to PLOB [8]. It only shows that its author (Namiki) did not understand their methods...

May 03 2016 15:03 UTC

Perhaps this manuscript should not even exist. It would claim to prove the results of PLOB (http://arxiv.org/abs/1510.08863) with a "regular path". The problem is that this author just did not understand the methods in PLOB!
There is absolutely no problem with Choi states with infinite energy. In fact, PLOB handles the case of bosonic Gaussian channels by using suitable sequences of energy-bounded Choi matrices. They then take the asymptotic limit which is regular, continuous and bounded. There is no illness whatsoever....

May 03 2016 06:23 UTC