# Tag Info

Accepted

### Can't quantum teleportation be superluminal some percentage of times?

This is really a subtle point. You are right that in 25% of the cases, Bob will randomly chose the "correct" measurement basis and thus get the correct value. However, there is no way for Bob to ...
• 3,861
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### Is High-Fidelity Quantum-Entanglement Data-Transfer Real?

The paper is about quantum teleportation, which is a process enabled by entanglement. However, it does not provide faster-than-light communication. The complete process of teleportation always needs a ...
• 12.4k
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### How is quantum teleportation any better than regular transfer of information?

There are several reasons quantum teleportation is a useful way to move qubits, even if you already have a normal quantum channel. Latency reduction. Suppose the quantum channel has decent bandwidth ...
• 5,924
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### What is the 3 dB limit of standard parametric squeezing techniques?

As often in continuous variable quantum physics, it is a case where the “limit” is not a hard one (like “no information faster than $c$” in relativity), but a value at which interesting things occurs, ...
• 10.6k
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### In quantum teleportation, how do the measurement & reconstruction steps work mathematically?

There are two ways to do this. There's the easy, intuitive way, and the complicated, mathematically-rigorous way. Here I'll go over the latter: The Density Operator The density operator is an ...
• 263
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### How does the quantum teleportation protocol not violate the no-cloning theorem?

You could think that quantum teleportation violates the no-cloning theorem, but it is actually not the case. Indeed, the original state $|\psi\rangle$ has not been duplicated, since after the ...
• 576
Accepted

### What's wrong with my teleporter?

Your error is in assuming that if D1 does not measure a photon, it will necessarily be measured by D2. But that is not true! If you're sending half the probability amplitude to D1, and half to D2, ...
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### University of Delft results regarding quantum teleportation of information

I haven't read the links in any detail, but it might help you to understand that teleportation also requires classical communication to work. (Sorry if you already understood this.) In order to ...
• 14.6k

### How is quantum teleportation any better than regular transfer of information?

The key aspect that sets quantum teleportation apart from the regular classical transfer of information is that it enables Alice to send information that even she does not have access to. The ...
• 124k
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### Quantum teleportation with moving Alice and Bob

The relativity of simultaneity ensures that for non-causal events, the order in which they happen can depend on the reference frame you choose. However, in the case of teleportation, if Bob chooses ...
• 1,146
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### Why is quantum teleportation needed to transmit a state?

If all you want to do is recreate a single quantum state somewhere else, and you have the ability to create exactly this state as many times as you want, and you don't care about exact recreation ...
• 34.7k
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### Quantum teleportation and macroscopic objects

Quantum teleportation is a concept of transferring quantum states of matter. Not teleporting matter itself. To "clone" an object to the destination, you need to have the same material as the object ...
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### What's wrong with my teleporter?

The issue is your first assumption. While it's true that the photon can have an amplitude to be in multiple places at once, it can only be measured to be in one place. For example, suppose we split ...
• 95.5k
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### How can information be communicated with entanglement?

You are right. Bob can only determine the state of his particle (without measuring it) once he receives information from Alice about the outcome of her measurement - and this information can be ...
• 35.6k

### If there's a small probability particles may teleport anywhere in an infinite Universe, shouldn't stars pop up in existence close to us ever so often?

No, an infinite universe does not make this likely. As the distance from earth increases (on cosmological scales) the number of atoms increases with the square of the distance. So, in order for the ...
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• 2,184
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### Can a non-entangled qubit be teleported by entangling it?

Quantum teleportation works on any qubit. It isn't restricted to only working on entangled qubits. It works on unentangled qubits. Quantum teleportation does require the sender and receiver to have ...
• 5,924

### Can a non-entangled qubit be teleported by entangling it?

Take a pair of qubits in a maximally entangled state $\phi=A\otimes B+B\otimes A$. (Here $A$ and $B$ are a basis for the state space of a single qubit.) One stays with you, the other resides at the ...
• 12.7k

### What's wrong with my teleporter?

This fails the "is there something quantum mechanical about this test setup" basic requirement for asking if quantum teleportation allows superluminal transport of information. Your setup could be ...
• 35.2k

### On what qubit does Bob perform Pauli Correction in Quantum teleportation protocol?

I think your lecture notes are not so clear - I would instead just look at Wikipedia. 1) You are correct that the 'Pauli correction' is to apply a correction operator (either $X$, $Z$, or some ...
• 1,356
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### How do 3 physically entangled particles work?

"Say a particle split into 3 particles that are all entangled to each other, ... if I'm to measure only one of them can I thus predict the quantum states of the other two?" Well it depends on how ...
• 12.4k

### Patent for full body teleportation system using wormholes

To answer your first question, anyone can patent anything, it does not have to work even in theory, if you have some data behind it you can patent it To answer your second question... I cannot ...
If Alice observes an electron from a maximally entangled EPR pair, the expectation value of the spin is always $$\langle \vec S \rangle = 0,$$ not the cosine indicated by the OP. It's because the EPR ...