Questions tagged [teleportation]
Quantum teleportation is a process by which quantum information (e.g. the exact state of an atom or photon) can be transmitted (exactly, in principle) from one location to another, with the help of classical communication and previously shared quantum entanglement between the sending and receiving location. (Wikipedia)
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What is the difference between quantum teleportation and quantum entanglement with dense coding?
What is the actual difference between quantum teleportation and quantum entanglement with dense coding.
Wikipedia says:
Quantum teleportation is a technique for transferring quantum information from ...
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Phase shift on qiskit quantum teleportation simulation
I wonder in Qiskit why the phase shift occurred in my simulation and how I can turn it off.
I posted another question regarding the same simulation here, and while I tried to solve this on my own, I ...
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Does Bob know the state of the qubit Alice teleported after the completion of the teleportation protocol?
Notation: $|\text{Alice}_{1\,\,}\text{Alice}_{2\,\,}\text{Bob}_{1}\rangle$
Alice and Bob shared an entangled state, say a Bell state $| \Phi_{+}\rangle = \frac{1}{\sqrt{2}}\bigg[|00\rangle + |11\...
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Why is a Bell state involved in quantum teleportation?
Notation: $|\text{qubit}_{1}, ..., \text{qubit}_{N}\rangle$.
The goal of quantum teleportation is to send quantum information using classical bits.
A source transmits a state $|\psi\rangle_{A_{0}} = \...
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$CNOT$ teleportation in ZX-calculus: how to simplify my circuit further?
I am stuck in simplyfing the following cNOT teleportation in ZX-calculus. I don't know how to proceed further. The circuit I start from is taken from this thesis (Fig 2.14, page 22).
Which property ...
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Can quantum teleportation be used to break BB84?
BB84 is a key quantum distribution scheme, which is supposed to be "provably secure" and resistant to an individual eavesdropper. However, from what I can tell, is seems as if one could ...
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Use of maximally entangled states in dense coding and quantum teleportation
In studying about the procedures of superdense coding and quantum teleportation, I have seen that maximally entangled states are used in both cases to show that how entanglement can be used as ...
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CNOT and quantum entanglement
I have the following problem:
"Consider two parties: Alice in possession of the one-qubit state |ψ⟩ = α|0⟩ + β|1⟩, and Bob who starts with a qubit in the state |0⟩
Show that Alice can teleport ...
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New QASM2ParseError for old circuit on IBM composer
A while ago I wrote an example of quantum teleportation circuit in the IBM Composer which ran fine as of three days ago. Yesterday, however, when I try to run the circuit, I get the following error:
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Injecting arbitrary rotations into the surface code
I'm trying to find an exact resource count for specific QFTs.
A QFT generally needs small power-of-two rotations. These can be constructed out of Clifford+T, but I'm wondering if one can inject them ...
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What is the exact mathematical content of the no-teleportation theorem?
My question concerns the following theorem (not to be confused with quantum teleportation protocols): what is the exact mathematical content of this theorem? After all any (pure) quantum state (say in ...
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Clarification regarding application of distributive property in "quantum teleportation" example
For context, this is from Page 27 of Nielsen, M. A., & Chuang, I. L. (2010). Quantum Computation and Quantum Information: 10th Anniversary Edition. Cambridge University Press:
She then sends the ...
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Is circuit cutting equivalent in anyway to quantum teleportation?
I've been introduced recently to circuit cutting, and after seeing the 4 orthogonal measurements with their 8 corresponding initializations but no initial transfer of classical info, the first thing ...
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Is quantum energy teleportation a specific version of quantum teleportation?
I just read another sensationally titled article in Quanta magazine, Physicists Use Quantum Mechanics to Pull Energy out of Nothing where they discuss the work of Masahiro Hotta on transferring energy ...
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Does quantum teleportation transmit entanglement between nodes?
I have seen that a pure state, $$|\psi\rangle=\alpha|0\rangle+\beta|1\rangle$$, can be teleported from Alice to Bob using Bell measurements and an operation, provided Alice and Bob share the EPR state,...
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References that use trace distance to calculate quality of teleportation
State fidelity is the most used measure to compute similarity of input and output states in articles dealing with a quantum teleportation.
For my research, I would like to know whether are there ...
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Can $2^n$ bits be sent with $n$ instances of quantum teleportation?
So, right now these are two pieces of information I've been told are correct:
Quantum teleportation can send a single qubit from Alice to Bob, with two classical bits
$n$ qubits can store $2^n$ ...
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Can teleportation violate the no-cloning theorem with 3 entangled qubits?
I saw the How to prove teleportation does not violate no-cloning theorem? question.
But I want to address this issue from a different angle.
What if instead of entangling 2 qubits, we would have ...
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Strange inequivalence between superdense coding and teleportation
Let the fidelity between two quantum states be defined as
$$F(\rho, \sigma) = \|\sqrt{\rho}\sqrt{\sigma}\|_1.$$
If $\rho = \vert\psi\rangle\langle\psi\vert$, then $F(\rho, \sigma) = \sqrt{\langle\psi\...
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How does quantum teleportation work with mixed shared states?
I am given the scenario that instead of the two parties (A & B) sharing the bell state $|\phi_+\rangle$ they share the mixture $\rho_\lambda = \lambda|\phi_+\rangle\langle\phi_+|+(1-\lambda)\frac{\...
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Do quantum teleportation require transmission media?
It said on wikipedia:
Because classical information needs to be sent, quantum teleportation cannot occur faster than the speed of light.
So does it mean quantum communication specifically ...
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Can separable, but non-valid "states", be used as a resource to generate entanglement?
Suppose two parties, Alice and Bob, who are separated share the "state" $\sigma_{AB}=|0\rangle\langle1|_A\otimes |0\rangle\langle1|_B$. Of course, this not a valid quantum state as it does ...
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What are the 2022 Nobel Prize winning papers of Alain Aspect, John Clauser, and Anton Zeilinger, and how do they fit into the timeline of QIS?
The 2022 Nobel Prize in Physics was awarded to Alain Aspect, John Clauser, and Anton Zeilinger for "experiments with entangled photons... pioneering quantum information science".
Presumably ...
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Is quantum teleportation fully secure (in principle)?
Suppose two parties Alice and Bob have access to as many EPR pairs as needed, with each one having a qubit of each pair. Now Alice can create a sequence of qubit states $|i_{1}\rangle, |i_{2}\rangle, |...
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How is the grouping of terms done in the calculations for the teleportation circuit?
I have a CS background and am studying quantum computing by myself. Struggling at the moment with the Dirac notation for the teleportation circuit.
Here we go:
The circuit starts with the EPR pair ...
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How to teleport an entangled state via the two-qubit Heisenberg model?
I saw many articles that talk about entanglement teleportation via the two-qubit Heisenberg model as a quantum channel
for example look at this artiles
https://arxiv.org/ftp/arxiv/papers/0808/0808....
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Why doesn't reading the ancilla qubit in Quantum Error Correction kill entanglement?
In Quantum Error Correction we have ancilla qubits (in gray) that will be entangled with the pair of bits we want to check.
Because we don't want to directly measure the "main" qubits (in ...
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Quantum teleportation transmits the exact qubit even when the state $\alpha\vert 1\rangle+\beta\vert 0\rangle$ has arbitrary $\alpha,\beta$?
I saw the concept of quantum teleportation, and they say you have a pre-shared state between Alice and Bob, such as $\alpha\vert 1\rangle+\beta\vert 0\rangle$, with $\alpha=\beta=\frac{1}{\sqrt{2}}$. ...
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General Proof of the Statement that You Need $1$ Ebit and $2$ Bits to Teleport $1$ Qubit?
I understand from the standard teleportation protocol that 1 ebit is used up in teleporting 1 qubit and thus, cannot be used again -- and thus, we need 1 fresh ebit of shared entanglement between ...
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How Quickly Can We Entangle a Pair of Unentangled Qubits Without Using Pre-existing Entanglement?
The Set-Up
Let's say we want to entangle two qubits $\phi_a,\phi_b$ (at locations $a$ and $b$ respectively) that are spatially separated by distance $d$ (in natural units) at a given instance of time.
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how to prove quantum teleportation can't be achieved by sending only one classical bit
If Alice and Bob share an entangled state like the EPR state, by sending only two classical bits, Alice can transfer one qubit to Bob by means of quantum teleportation (see also Section 1.3.7 of http:/...
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Can we teleport an arbitrary two-qubit state? [duplicate]
Can we teleport a quantum register $a\left|00\right> + b\left|01\right> + c\left|10\right> + d\left|11\right>$ ? How can I visualize the output for this? I was looking at the https://...
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Gate teleportation between different QEC codes
I've heard people mention that one can teleport a gate from one QEC code into another, but I am trying to better understand operationally what exactly this entails, and whether there are any ...
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are the operation applied in Teleportation circuit fixed?
I implemented teleportation described on this page: Teleporation
Circuit diagram is as follows:
since we use entanglement for teleportation, as entanglement is done before 1st barrier, just wanted to ...
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What is the logic behind applying $X$ or $Z$ conditionally to the received bits?
I implemented teleportation described on this page: Teleporation
Circuit is as follows:
Here, as we are trying to teleport the quantum state from Alice (q0) to Bob(q2).
Bob, on receiving the bits ...
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What is the time overhead for fault-tolerant gate teleportation?
The gate teleportation protocol (https://arxiv.org/abs/quant-ph/9908010) has a step where it utilizes cat state measurement of transversal operators. Since cat states can not detect phase errors it is ...
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What is a realistic model for simulating physical tampering of a channel? (ex: nearby vibrations)
Somewhat related to this question.
Imagine a fully functioning quantum network, where qubits are transported via fiber optic cable. If vibrations were to physically tamper with a channel in such a ...
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Why does gate teleportation allow to implement nonlocal operations via local ones?
In (Gottesman and Chuang 1999), when discussing quantum gate teleportation, they mention how it can be used to implement nonlocal gates such as a CNOT, by only using (classically controlled) local ...
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How does quantum gate teleportation differ from state teleportation?
As described e.g. in this post, quantum gate teleportation can be framed as a variation of quantum state teleportation where a gate is applied beforehand on the receiver, and this results in the final ...
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Why do we use the Bell state $|00\rangle+|11\rangle$ for quantum teleportation?
In the quantum teleportation protocol we use the Bell state given by
$$\frac{1}{\sqrt{2}} \left( |00\rangle + |11\rangle\right). $$
My intuition tells me this works is because we can transform this ...
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Quantum Teleportation Algorithm Always Ends in State $|0\rangle$
I'm trying to put together a demo using the Quantum Teleportation example provided by qiskit.
The quantum circuit runs as intended when it's initialized to the state $|0\rangle$, and the measured ...
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How to simulate the state of a system after partial measurement?
Based on the answers at here and here, I have a quantum simulator which implements the operations described in the classic Teleporting an Unknown Quantum State. Careful comparison of circuits with the ...
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Why do unitaries act on maximally entangled states as $(U\otimes I)|\phi\rangle=(I\otimes U^T)|\phi\rangle$?
I was reading about teleportation which had the following Bell counterpart in $N$ dimensions
$|{\phi}\rangle=\sum_{i=0}^{N-1}|i\rangle\otimes|i\rangle$. The next line was
$$(U\otimes I)|\phi\rangle=\...
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Getting different sets of plots for the teleportation algorithm in Composer and Lab
I tried recreating the quantum teleportation circuit (in the Qiskit Foundation Youtube Playlist) both in Lab and Composer and getting different plots for each.
Here is circuit and histogram from ...
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Decompose bell measurement gate into combination of controlled-not gates and one-qubit gates
OPENQASM2.0 has only one two-qubit gate: controlled not. For a teleportation experiment, I need to perform a measurement in the Bell basis. That is, I need a two-qubit gate with matrix representation
$...
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Why doesn't this simpler teleportation idea work?
This circuit:
The first (upper) qubit is the one we want to teleport, so could start it any state, call $\alpha|0\rangle+\beta|1\rangle$. Our goal is to teleport it to the third (bottom) bit.
After ...
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Is it possible to have Quantum Teleportation Protocol without using classical channel?
I'm still learning Quantum Information right now, especially with Quantum Teleportation (QT). I have found an interesting article suggesting a Simplified Protocol of QT that doesn't need classical ...
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Strange behaviour of IdentityGate IGate in IBM Q Composer
Can anyone explain the strange impact of the IGate in the enclosed quantum teleportation setup in view of the computational basis states? Any help is welcome!
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Generalizing the circuit for quantum teleportation for $n$-qubit states?
So the usual quantum circuit I know for quantum teleportation allows for the teleportation of the state on a single qubit, in the following way:
How easy is to generalize this algorithm to allow for ...
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What is the name of this "ancilla based" process to implement gates
I just want to know if there is a specific name for the implementation of a gate on the top qubit with the help of the bottom qubit, represented on this image:
It looks like gate teleportation but it ...
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