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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Post-selection applied to quantum teleportation

In this answer, it is stated that applying post-selection to quantum teleportation results in Alice communicating to Bob backwards in time. Could someone explain how this works? I am particularly ...
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How does Bell measurement work in the teleportation?

I'm a complete beginner and one of the first things I was taught was the teleportation protocol. In the protocol, the party sending its state (which we call say $|\phi\rangle$) makes a Bell ...
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Is communication possible with entanglement?

From what I gather, communication is not possible with quantum mechanics. With the experiment on teleportation, entanglement is referred to as coordination and not communication. However, my belief is ...
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In quantum teleportation what is the need for the extra X/Z gate after classical information is sent from Alice to Bob?

In the Qiskit textbook, at step 4, Bob who has received the classical bits from Alice then needs to apply a X and/or Z gate depending on what the classical bits received are, why is that?
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Transferring GHZ state onto some qubits

This question is just my effort that I made by understanding the previous answers to my questions . I have a GHZ state $|000\rangle+|111\rangle$ (please ignore the normalizing constant). For ...
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Cluster/Graph state teleportation

I came across somewhere about the circuit diagram that depicts the teleportation of a 4-qubit cluster state. Here it is Let me tell what i understood. The qubits on the first two wires give the state ...
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How does quantum teleportation relate to quantum encryption?

I am in grade 11 and am trying to work on a project, but I find this question a little confusing. I am trying to talk about the implications of quantum teleportation, specifically quantum encryption ...
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Rearrangement of qubits in Quantum Teleportation Protocol

I have been reading Quantum Teleportation (Pg. 27) from Nielsen and Chuang and noticed that after the Hadamard operation, the state obtained was re-written by regrouping the terms to obtain the ...
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How should I understand that protocol has worked correctly by histogram?

I'm trying to simulate quantum secret sharing protocol HBB99 I've read the paper "Quantum secret sharing" by Hillery, Bužek and Berthiaume (Phys. Rev. A, 1999; preprint on arXiv) and I have a question ...
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In Qiskit quantum teleportation protocol, why they use CZ and CX gate at the end?

I understand the simple quantum teleportation protocol and why it uses X and Z gate at the end of the circuit. I was researching about the Qiskit and I came across this video https://www.youtube....
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Why can’t I use quantum teleportation to transmit data FTL 1/4 of the time?

$\newcommand{\bra}[1]{\left<#1\right|}\newcommand{\ket}[1]{\left|#1\right>}\newcommand{\bk}[2]{\left<#1\middle|#2\right>}\newcommand{\bke}[3]{\left<#1\middle|#2\middle|#3\right>}$ ...
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How does Teleportation based Error Correction (TEC) detect and correct loss/erasure errors?

I'm looking at papers like Demonstration of teleportation-based error correction in the IBM quantum computer (page) 10 and Role of syndrome information on a one-way quantum repeater using ...
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What does it look like to split an EPR pair?

I am reading Quantum Computation and Quantum Information by Michael A. Nielsen & Isaac L. Chuang, and I am confused about a concept presented in Section 1.3.7: Quantum Teleportation. The book ...
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Does principle of deffered measurement imply information can travel faster than light?

I have been reading the book by Michael A Nielsen and Isaac Chuang and came across the principle of deferred measurement. They showed using this principle how the circuit for quantum teleportation can ...
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Entanglement Swapping Circuit

I implemented 2 versions of the entanglement swapping circuit in IBM Q. One is using classical measurement to control X, Z gates. Another is just us C-NOT and Controlled-Z. They should be equivalent. ...
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How does the teleportation circuit work after the initial entanglement?

I'm trying to understand why we do what we do when we teleport a state from Alice's first qubit to Bob's qubit. I understand the initial entanglement, but could use help walking through the program. ...
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How to implement controlled gate based on measurement (quantum teleportation)?

I am implementing the teleportation algorithm on IBM Q Experience (GUI interface). Certain operations on the third qubit are only performed if the classical measurement result is 1, for example ...
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Generalising the standard quantum teleportation protocol: what are the possible unitaries?

Consider the standard quantum teleportation scheme. Let the first register hold the state $\newcommand{\ket}[1]{|#1\rangle}\ket\psi$ to be teleported, and the second register be the one shared between ...
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Teleportation and non-orthogonal measurement operators

Consider the simple state teleportation gadget below. Measuring the entangled state after the CZ gate in the $X$ eigenbasis (equivalent to first applying $H$ and then measuring in computational basis) ...
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Compute the output of the quantum teleportation circuit

Sender and receiver use the teleportation protocol, where the sender teleports a quantum state $\left| \varphi \right>=\alpha\left| 0 \right> + \beta \left|1\right>$ to the receiver. I want ...
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Quantum teleportation between two computer chips, how relevant?

After stumbling upon this recent news article: Information teleported between two computer chips for the first time (which references a "Nature Physics" publication Chip-to-chip quantum teleportation ...
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Problem involving entanglement swapping

I'm trying to solve a problem. I have my own approach to it, as the one in the textbook seems overly complicated. I tried using my own approach, but I'm not sure if what I found was a coincidence or ...
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Is it possible to write a Q# teleportation code which returns a qubit?

Is it possible to write a Q# teleportation code which returns a qubit? Thanks.
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Is quantum teleportation a natural phenomenon?

Quantum teleportation is a reasonably well-defined physical process, whereby a quantum state is transferred between two separated entities that already share an entangled state. It's been demonstrated ...
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Understanding quantum teleportation algorithm from qiskit tutorials

I am very new to quantum computing and I have recently started to experiment with qiskit module in python, by following tutorials and implementing simple algorithms....
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Does this setup violate relativity?

Suppose Alice needs to transmit a bit of information about something which happened just before $t = 0$ to Bob who is light years away from Alice. Entangled pairs of qubits, $\left|00\right> + \...
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Entanglement and teleportation in quantum annealing and parallel computation

In classical optimization problems, some objective function's surface serves as a landscape for finding its minimum through minimization algorithms. Instead of your typical U-shaped objective ...
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Trying to build a circuit for quantum teleportation on IBMQ I get ERROR_RUNNING_JOB error

I am trying to build a circuit for quantum teleportation. On the simulator, everything runs fine and according to expectations, however, I am not able to run the algorithm on the real quantum ...
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Understanding shared Bell states from quantum entanglement

I'm trying to understand an entanglement swapping derivation provided in this PDF (pages 2 - 3) I have several things about this process that I don't understand, and I was hoping someone could ...
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Evaluate the following teleportation equation for $U = ZX$ and $a = 0, b = 0$

When I evaluate the following equation using $U = ZX$ and $a = 0, b = 0$ [for Bell state], I am getting LHS not equal to RHS. Before describing the protocol, let us first review the teleportation ...
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What is the resultant composite quantum state after the transfer?

Suppose Alice has the following state $|\Psi\rangle = \frac{1}{\sqrt2} (|10\rangle + |11\rangle)$ If Alice transfers 1st qubit to Bob then is this the resultant composite system state after transfer? ...
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Explain matrix multiplication math operations of a Hadamard gate after a phase gate

Starting with $|0\rangle$, I would like to understand how the probability values of 85.4% $|0\rangle$ and 14.6% $|1\rangle$ are derived from the payload circuit below? After applying the 45 degree ...
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In what ways can qubits be used for applications that do not require entanglement?

Many good questions on this site have explored how entanglement lies at the boundary between the quantum world and the classical. For example in computational speedups, or teleportation or superdense ...
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How to understand a phase operation between 2 Hadamard gates?

I would like to understand this image, of a "payload preparation" gate. A single H gate will create a superposition, while the phase will rotate 45 degrees. What does the second H gate do in this ...
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How to integrate Simulaqron on ProjectQ

I am trying to simulate quantum teleportation on ProjectQ using simulaqron (enabling me to use quantum internet for teleportation) however I am not sure if my approach is right. In the working paper ...
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Quantum gate teleportation T gate

I am faced with the problem of teleporting certain gates using modified Bell states. For example, I have solved the problem with the $S$ gate, which is defined as following: Alice and Bob share a ...
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Quantum teleportation with “noisy” entangled state

This is actually an exercise from Preskill (chapter 4, new version 4.4). So they are asking about the fidelity of teleporting a random pure quantum state from Bob to Alice, who both have one qubit of ...
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Understanding this description of teleportation

In the context of quantum teleportation, my lecturer writes the following (note that I assume the reader is familiar with the circuit): If the measurement of the first qubit is 0 and the measurement ...
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Quantum teleportation of a state, from one of two bases

I'm watching Christian Schaffner's talk on quantum position-based cryptography (link here) and have a question about a particular application of teleportation. At about the 16:40 mark, he seems to ...
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How to complete this teleportation circuit? How to create a copy of $|\psi〉$?

This is a quantum circuit. M represents the act of making a measurement on the first two qubits. The circuit is supposed to transfer the state $|\psi\rangle = a |0\rangle + b |1\rangle$ ($a, b \in \...
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Are superdense coding and teleportation just a prototype or the 'only' type?

I am interested to know if models in quantum mechanics and techniques like superdense coding teleportation are just single cases where they were found to work. Or rather just a prototype of many other ...
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How to prove teleportation does not violate no-cloning theorem?

For a given teleportation process as depicted in the figure, how one can say that teleporting the qubit state $|q\rangle$ has not cloned at the end of Bob's measurement?
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How we can describe entanglement from measurement and resource perspectives?

When we read books on quantum computing and information theory, specifically in entanglement we find some distinguishability between those who focus on entanglement as a resource or use it as an ...
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Why is measurement needed in teleportation?

One of the postulates of QC is, that measurements in every circuit can be postponed or never performed in a circuit while achieving the same functionality of the circuit (at least this the way I ...
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Can we teleport a human or send information faster than light using quantum teleportation?

What does quantum teleportation mean? Is it something that will allow us to send information faster than the light? Can we teleport a human with it?
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Quantum teleportation with moving Alice and Bob

I have questions regarding quantum teleportation, which keep confusing me. Suppose Alice and Bob are in the same inertial frame $K$, and at time $t$ (in $K$) Alice teleports a quantum state to Bob. ...
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Quantum teleportation over continuous variables?

I came across this circuit diagram for CV quantum state teleportation: Source: Xanadu Strawberry Fields: Docs / Quantum algorithms / State teleportation It was accompanied by a brief ...
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What does teleportation have to do w/ XOR linked lists? [closed]

I am trying to wrap my head around the correlation between repeating teleportation & XOR linked lists. I understand that: "the quantum equivalent of the one time pad (i.e. XORing a message with ...
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Generalizing quantum teleportation for qudits

In an answer to a previous question, Generalization for n quantum teleportations, Craig Gidney states: The more complicated way to generalize teleportation is figuring out how to make it work on ...
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Why can't you run a teleportation circuit on an IBM Q device?

I'm studying teleportation circuits with this tutorial and just out of curiosity, why can't a teleportation circuit be run on an IBM Q device?