No, you have to transmit every time you want to transmit.
When measuring one particle of an entangled pair and you get say "spin up", you know immediately that if someone measures the other particle (with the same measurement settings) they'll get "spin down", and vice versa.
The chance that you get "spin up" or "spin down" is 50/50 and, as far as we know, cannot be affected or determined in advance.
So, on the receiving end, they measure some random combination of "spin up" and "spin down". Without anything else, this information is for all intents and purposes noise.
What you can do however, is to send a message using regular means with what you measured: "up, down, down, up, down". Ok, at least now they can check that what they got was the exact opposite. However that still doesn't tell them anything.
So instead what you do is that you change the measurement settings, and send via regular means not just your measurement results but also your measurement settings. So you'll send "H left, V down, V up, H left, H right". The recipient will then take the measurement settings (H or V) and measure the entangled particles in the same way you did, and then note down that they get the opposite.
Note now that you suddenly got a way to communicate some actual information. By agreeing in advance that a Vertical measurement means 0 and a Horizontal measurement means 1, you can send information to the recipient.
However also note that you had to make a measurement of your particles and then send the results using regular means, limited by the speed of light. So why bother with this complicated setup? Why not just send the data without all this entangled stuff?
And indeed, for just sending plain messages it makes no sense to use entangled pairs.
However as I noted in my other post, the inability to clone entangled states means an eavesdropper can be detected using the entangled setup.
When measuring one particle of an entangled pair and you get say "spin up", you know immediately that if someone measures the other particle (with the same measurement settings) they'll get "spin down", and vice versa.
The chance that you get "spin up" or "spin down" is 50/50 and, as far as we know, cannot be affected or determined in advance.
So, on the receiving end, they measure some random combination of "spin up" and "spin down". Without anything else, this information is for all intents and purposes noise.
What you can do however, is to send a message using regular means with what you measured: "up, down, down, up, down". Ok, at least now they can check that what they got was the exact opposite. However that still doesn't tell them anything.
So instead what you do is that you change the measurement settings, and send via regular means not just your measurement results but also your measurement settings. So you'll send "H left, V down, V up, H left, H right". The recipient will then take the measurement settings (H or V) and measure the entangled particles in the same way you did, and then note down that they get the opposite.
Note now that you suddenly got a way to communicate some actual information. By agreeing in advance that a Vertical measurement means 0 and a Horizontal measurement means 1, you can send information to the recipient.
However also note that you had to make a measurement of your particles and then send the results using regular means, limited by the speed of light. So why bother with this complicated setup? Why not just send the data without all this entangled stuff?
And indeed, for just sending plain messages it makes no sense to use entangled pairs.
However as I noted in my other post, the inability to clone entangled states means an eavesdropper can be detected using the entangled setup.