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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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In quantum teleportation, why does measuring entanglement not destroy the whole state?

In quantum teleportation, we have three qubits. Sender, receiver and ancillary. First, we entangle the ancillary and target qubit. Next, we entangle ancillary and sender qubits. Now, the whole system ...
Mayukh Mukherjee's user avatar
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Can we perform teleported-error-correction with noisy Bell pairs?

It is well-known that in https://arxiv.org/abs/quant-ph/0312190 that error correction can be performed by teleportation on the logical level, so prepare one logical Bell pair and (logical?) Bell ...
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How does quantum teleportation not lose information?

This may be a bit of an elementary question, but I think understanding it will help me understand fundamentally what makes quantum algorithms a bit magical. Alice starts with a message she wants to ...
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Teleportation of Transversal Hadamard Gate from the $[[8,3,2]]$ to $[[4,2,2]]$ codes

I'm trying to understand the circuit from Appendix A of the paper Fault-Tolerant One-Bit Addition with the Smallest Interesting Colour Code. Here the top 3 qubits represent the 3 logical qubits of ...
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Why does this not break the security of quantum teleportation

Reposted from my post on the physics stack exchange, apparently this is a better place. I am taking an course on quantum mechanics, and we have just encountered the quantum teleportation protocol that ...
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quantum teleportation with shared state and teleported state in bloch representation

Suppose that two parties (Alice and Bob) share an entangled state $$ \rho_F = F \lvert \phi^+ \rangle \langle \phi^+ \rvert + \frac{1-F}{3} \left( I \otimes I - \lvert \phi^+ \rangle \langle \phi^+ \...
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Quantum teleportation of unknown qubit when the entangled state is not a Bell state

Assume Bob and Alice have two particles with a prior entanglement: $A$ and $B$. The entangled state $|Ψ⟩$ is maximally entangled, and $$|Ψ⟩ = \frac{1}{\sqrt{2}}(|00⟩ + j|11⟩)\,,$$ where $j$ is a ...
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2-Qubit Gate Teleportation with 1 Maximally Entangled State for Distributed Computation

$\newcommand{\ket}[1]{|#1\rangle}$ I search for quantum circuits/protocols that enable distributed quantum computation of a 2-qubit gate using gate teleportation. Let me explain the desired scenario ...
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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 ...
Physiclá's user avatar
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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 $|\psi\rangle_{A_{0}} = \...
Physkid's user avatar
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$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 ...
Marco Fellous-Asiani's user avatar
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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 ...
Samuel Jaramillo's user avatar
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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: ...
Lachlan Belcher's user avatar
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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 ...
Alan Whitteaker's user avatar
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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 ...
Guillermo Abad Lopéz's user avatar
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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{\...
Luca Ion's user avatar
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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 ...
Muhammad Ikhwan Perwira's user avatar
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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 ...
Hans Schmuber's user avatar
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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, |...
Maximal Ideal's user avatar
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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 ...
neilson's user avatar
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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. ...
FreeAssange's user avatar
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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 ...
Vinay Sharma's user avatar
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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 ...
Vinay Sharma's user avatar
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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 ...
Seyed's user avatar
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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 ...
Quantum Guy 123's user avatar
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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 ...
WiredInstruction's user avatar
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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 ...
Anna Naden's user avatar