It's crazy that you took the time to create such a good series on RUclips for free so that anyone can try to learn these things. Thank you so much Sir.
how can we guarantee that the time required to transmit the information by Alice change the state of entangled qubits? Suppose ALice sends to Bob the information that Bob needs to apply Z gate, but Bob being a lightyear away.... gets this information a year later... will this interval of a year not change the state of entangled qubits to something different?
Bob's states are paired with the corresponding states of the two qubits held by Alice. After Alice performs the Bell measurement the superpositions "collapses" and Bob ends up with one of the four states. He learns which one when Alice communicates the result of the Bell measurement. See also: thosgood.com/quantum-info/book/chapter5.html#quantum-teleportation
how is the bell measurement performed? what is the mathematical operation? i dont see how alice can get the information of the states othe 2nd and third qubit
In what context can Quantum teleportation be a better solution than just transferring psi directly? I mean that the shared entangled state already needed a way to travel without collapsing. Also It doesn't seem safer than Quantum Key distribution etc... I didn't figure out what was the main advantage of this technique
It's a better solution in pretty much any situation where you do not know the state of the qubit you are trying to transfer. This because the quantum states can decay when transferred, and so it is more desirable to send many copies that can be combined at the end to reduce noise, known as quantum distillation. But you can't do this with a qubit you have no idea what the state is. So you could do it with a Bell state and teleport the qubit through the Bell state safely.
@@amihart9269 Ok I see but aren't the entangled qubits also subject to decay when transfered ? Why would the entangled qubits be more pratcile to transfer or less error prone. Thank you very much for your first reply anyway !
It's crazy that you took the time to create such a good series on RUclips for free so that anyone can try to learn these things. Thank you so much Sir.
Very clear explanation. Thank you for your lectures.
Good video teacher.
If Bob's state is |1> it will cause teleport error, right?
I think the prefactors of the decomposition of the state is wrong. Shouldn't it be 1/sqrt(2)*1/sqrt(4) ?
Yes, it should be 1/((2sqrt(2))
Does the state have to be maximally entangled? If yes, why?
how can we guarantee that the time required to transmit the information by Alice change the state of entangled qubits?
Suppose ALice sends to Bob the information that Bob needs to apply Z gate, but Bob being a lightyear away.... gets this information a year later...
will this interval of a year not change the state of entangled qubits to something different?
Shouldn't coefficients in right hand side be 1/(2sqrt(2))?
Are the 4 possible states Bob Received from Alice on the classical channel added together?
Bob's states are paired with the corresponding states of the two qubits held by Alice. After Alice performs the Bell measurement the superpositions "collapses" and Bob ends up with one of the four states. He learns which one when Alice communicates the result of the Bell measurement. See also: thosgood.com/quantum-info/book/chapter5.html#quantum-teleportation
how is the bell measurement performed? what is the mathematical operation? i dont see how alice can get the information of the states othe 2nd and third qubit
Great explanation - thank you !
Am I right to understand that there is actually a tensor product between Phi and Omega states, not "normal" multiplication?
Yup, tensor product.
In what context can Quantum teleportation be a better solution than just transferring psi directly? I mean that the shared entangled state already needed a way to travel without collapsing. Also It doesn't seem safer than Quantum Key distribution etc... I didn't figure out what was the main advantage of this technique
It's a better solution in pretty much any situation where you do not know the state of the qubit you are trying to transfer. This because the quantum states can decay when transferred, and so it is more desirable to send many copies that can be combined at the end to reduce noise, known as quantum distillation. But you can't do this with a qubit you have no idea what the state is. So you could do it with a Bell state and teleport the qubit through the Bell state safely.
@@amihart9269 Ok I see but aren't the entangled qubits also subject to decay when transfered ? Why would the entangled qubits be more pratcile to transfer or less error prone.
Thank you very much for your first reply anyway !
How does the rearrangement of terms on the bottom work. I’m sure there is a tensor product property I’m not using
no just elementary school algebra.. he should write the 1st qubit on the left tho
Sri telepoaran possible
good
Empathy