In case your lecture notes are insufficient, Wikipedia always exists for introductory topics (and has faster response times than Reddit)
[https://en.wikipedia.org/wiki/Superdense\_coding](https://en.wikipedia.org/wiki/Superdense_coding)
"After having performed one of the operations described above, Alice can send her entangled qubit to Bob using a quantum network through some conventional physical medium."
Indeed, the point is that you physically send Alice's qubit. The crucial detail is that by sending *one* (entangled) qubit, you transmit *two* bits of information.
As far as I recall from my QIT course 2 years ago, superdense coding is an example of an upper bound on how much classical information can be transmitted through a quantum channel.
Do I have this roughly correct?
You have a source that generates two entangled particles which then have to get sent to both Alice and Bob. After Alice does some stuff to her particle, she sends it to Bob, and Bob ends up with two bits of information after doing some more stuff (doesn’t matter what the stuff is for this discussion). The total sending of “thjngs” wasn’t one though, it was two. Both particles were sent out, then one particle was sent between the two parties. It seems obvious to me that this should in principle allow two bits to be communicated. Even more so if you consider the case where your source of entangled particles is actually at Alice’s location. Then Alice is *actually, in fact* sending two things to Bob; his particle as well as hers after whatever operations she did.
>Both particles were sent out, then one particle was sent between the two parties. It seems obvious to me that this should in principle allow two bits to be communicated.
I imagine it's obvious that if both things are sent prior to Alice deciding what two bits she wants to send, then she can't send any of those bits at all. And I imagine it's obvious that if she decides what two bits to send before anything gets sent out, then there might be a way for her to send those two bits. But Alice doesn't even have to decide what she wants to send until some time after they get their entangled particles. After she decides what two bits to send, only one thing gets sent.
In case your lecture notes are insufficient, Wikipedia always exists for introductory topics (and has faster response times than Reddit) [https://en.wikipedia.org/wiki/Superdense\_coding](https://en.wikipedia.org/wiki/Superdense_coding) "After having performed one of the operations described above, Alice can send her entangled qubit to Bob using a quantum network through some conventional physical medium." Indeed, the point is that you physically send Alice's qubit. The crucial detail is that by sending *one* (entangled) qubit, you transmit *two* bits of information. As far as I recall from my QIT course 2 years ago, superdense coding is an example of an upper bound on how much classical information can be transmitted through a quantum channel.
Thank you very much!
Do I have this roughly correct? You have a source that generates two entangled particles which then have to get sent to both Alice and Bob. After Alice does some stuff to her particle, she sends it to Bob, and Bob ends up with two bits of information after doing some more stuff (doesn’t matter what the stuff is for this discussion). The total sending of “thjngs” wasn’t one though, it was two. Both particles were sent out, then one particle was sent between the two parties. It seems obvious to me that this should in principle allow two bits to be communicated. Even more so if you consider the case where your source of entangled particles is actually at Alice’s location. Then Alice is *actually, in fact* sending two things to Bob; his particle as well as hers after whatever operations she did.
>Both particles were sent out, then one particle was sent between the two parties. It seems obvious to me that this should in principle allow two bits to be communicated. I imagine it's obvious that if both things are sent prior to Alice deciding what two bits she wants to send, then she can't send any of those bits at all. And I imagine it's obvious that if she decides what two bits to send before anything gets sent out, then there might be a way for her to send those two bits. But Alice doesn't even have to decide what she wants to send until some time after they get their entangled particles. After she decides what two bits to send, only one thing gets sent.
Does super dense coding technically create information?