Question

What is Entanglement and Teleportation of quantum mechanical particles? Please draw scheme for both and explain the mechanism.

Answer 1

Quantum Entanglement-

It is a process when the pairs or particles having independent quantum numbers are generated, or are in spatial proximity so that the quantum state of each particle is not described independently of the state of other particles. This inability to describe those states remain intact even if we separate those particles by a large distance. A system is said to be entangled if the quantum states of its constituents can't be factored as individual and acts as inseparable bundle.

The state of such an entangled system can be expressed as sum or superposition, and it will always have more than one term compulsorily. For example- consider 2 particles having distinct quantum state. Let's entangle them and then separate them by a large distance. Now if we check the values of 1st particle, they both will have a complimentary matching, that is they will be opposite in their values and yet matching

Quantum Teleportation

This is a process of transmission of quantum information form one place to another using quantum entanglement information between the sending and receiving location. Unlike what we see in fiction, it is, as of now usable for transporting information only and not matter.

Now lets see the mechanism of quantum entanglement using an example- If a person 'X' has a particle entangled by a particle owned by another person Y, and Y teleport it to another person Z, then we say that X's particle is entangled with Z's particle. All the particles will remain connected now so that the operation performed on one particle will be reflected by other particles.

And now for the mechanism of quantum teleportation, we proceed as follows

1. A pair of quantum entangled particles in known state is created.
2. One of the entangled particle is moved near that particle whose state is to be copied and other particle is moved near that particle on which we would like to copy the state
3. Now we measure the original and nearby entangled particles, and send the outcome of these measurements to the copy
4. Depending on these outcomes, we perform some operations on combined state of the copy and then as a result, the copied particle is obtained in same state as that of original