What is Quantum Teleportation?

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California Institute of Technology, Fermilab, and NASA scientists have achieved quantum teleportation over a 44 kilometers distance with a 90 percent accuracy rate — but what is quantum teleportation, and why is it important? When you hear the word “teleportation,” you think of people moving instantaneously from one place to another. However, the truth of the matter is that quantum teleportation is different. Quantum teleportation is not like it is often portrayed in pop culture; you are not teleporting objects. However, you are instead “teleporting” information and data.

To understand quantum teleportation, you must first understand quantum entanglement. Imagine two boxes. One of the boxes has an apple, and the other has a banana. You do not know which one has the banana and which one has the apple, so the boxes are entangled, in some way. By opening one of the boxes, you will immediately know which box has the banana and which box has the apple. 

Now instead of thinking about apples and bananas, think of electrons. When electrons are close, their spin states can get entangled. Once the electrons are entangled, they can only have the opposite spin of one another. If you are to separate the entangled electrons across a vast distance — let’s say light-years away — and then measure the spin of one of them, if it is spinning up, the measurement will affect the spin of the other electron immediately across any distance because the entangled electrons can only have opposite spins. Albert Einstein called this phenomenon “spooky action at a distance.” The information of the entangled electrons traveled instantaneously, faster than the speed of light. In quantum entanglement, when particles are entangled, by measuring one of them you automatically affect and will know the state of the other.

Quantum teleportation is essentially the communication of quantum computers, the transfer of information. Unlike conventional computers, quantum computers cannot communicate by sending signals. Instead of sending 1s and 0s, they send qubits, which can carry 1s and 0s in a superposition. The qubit gets measured at another location, destroying the quantum state that it is in because when observing something in a superposition, the wave function collapses. To overcome this, quantum computers use entanglement to communicate, which is known as quantum teleportation. Instead of sending signals, information is essentially teleporting and being instantly received at the other end. 

With the recent success in the quantum teleportation field, scientists have begun laying the foundation for a quantum internet service, which will one day revolutionize computing.