Talk:Superdense coding

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"Quantum dense coding" and "Superdense coding" mean the same thing. The two articles should be merged asa proposed. Cryptonaut 02:36, 25 April 2006 (UTC)[reply]

I agree, merge 'em. —Keenan Pepper 02:45, 25 April 2006 (UTC)[reply]

This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Student editor(s): Djobes, Baileyruesch. Peer reviewers: Rronk96, Donaldfee.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 10:27, 17 January 2022 (UTC)[reply]

A IP user has requested that the diagram on this page the modified. They wrote: "Please flip b_1 and b_2 on sender's side! Thanks!" into the figure caption. I am moving the request here where it should be. I would make the change myself, but I'm not sure that it's actually correct or not. —♫CheChe♫ talk 15:21, 16 October 2017 (UTC)[reply]

Oh, also, I'm thinking of making a new SVG version of the diagram. If anyone can confirm that the requested change is correct, I would be happy to get on that. —♫CheChe♫ talk 15:23, 16 October 2017 (UTC)[reply]

The current version of the diagram is correct. --Robin (talk) 23:26, 16 June 2018 (UTC)[reply]

Bob does indeed need to apply a SWAP operation as his final step. In other words, [SWAP * kron(H,I) * CNOT] * [Alice's transformation] * [1;0;0;0] is the full process from the creation of two qubits to the final measurement, where the first term is Bob's decoding operation and the other two terms form one of the four Bell states. Note, however, that the computation of Bell state B11 in the "Encoding" section is also wrong: it appears someone mixed up the |01> and |10> states. 218.252.52.182 (talk) 21:19, 14 January 2020 (UTC)[reply]

The esteemed editor who keeps pondering "why" has apparently been too kind to point out both the transformations and their results are wrong. So much for "Details".

This page is missing experimental results even though the field is very active. For example:

this was the first experimental demonstration of superdense coding, where they achieved 1.58 bits per qubit (not a perfect 2): https://journals.aps.org/prl/pdf/10.1103/PhysRevLett.76.4656 (they used polarization of photons).

This year researchers exceeded the two-bit limit using high dimensional entanglement. http://advances.sciencemag.org/content/4/7/eaat9304

This group was the first transmit superdense coding over optical fiber. https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.050501 — Preceding unsigned comment added by Donaldfee (talk • contribs) 21:18, 30 November 2018 (UTC)[reply]

It seems like quantum dense coding, superdense coding, and dense coding are all used interchangeably. I think the first sentence should include them all to clarify that. Add an aka. — Preceding unsigned comment added by Donaldfee (talk • contribs) 21:22, 30 November 2018 (UTC)[reply]

Could there perhaps be some explanation of the overview statement "Alice must tell Bob which gate to apply after he receives the entangled qubit in order to obtain the correct classical bits." It does not seem to be explained anywhere. — Preceding unsigned comment added by 118.209.183.247 (talk) 14:36, 10 January 2019 (UTC) now signed by 118.209.183.247 (talk) 10:29, 12 January 2019 (UTC)johnjPerth[reply]

The video "Video superdense coding.ogg" seems to be selling an idea that isn't true. In the video A is connected to B via a single wavy line. This is contrary to the protocol which requires two qubits. The article even says "Without access to Bob's qubit, Eve is unable to get any information from Alice's qubit." The description in the External link "Superdense coding: how to send two bits using one qubit on YouTube by Michael Nielsen" is not as pretty, but much more accurate. Johnjbarton (talk) 16:55, 22 February 2025 (UTC)[reply]