Quantum Entanglement

Quantum entanglement is a property of quantum mechanics in which two or more objects in a system that are linked together can no longer be described singularly. In other words, if the two objects are somehow linked, even when separated by tremendous distances, one cannot be analyzed and described without paying the same attention to the other one. Quantum entanglement, while not known as that name, appeared around 1935 when Einstein, Podolsky and Rosen commented on it in their EPR paradox.

The theory suggests that two objects that are not linked are indeterminate without some sort of physical intervention. For example, when discussing spin, it can be measured that any given particle will be observed to either be having a spin-up or a spin-down. When measuring probability, it's easy to conclude that the likelihood of all particles behaving with either a spin-up or a spin-down is roughly 50%. That means half will do one; half will do the other.

If the particles get entangled, things change. Most importantly, the spin measurements described above become correlated. Observation notes that two out of an infinity number of possibilities states that when there are spins, the two particles will have opposite spins – one will be spin-up, the other will be spin-down. However, what observation also notes is that they will always have the same spin. That means if particle A and particle B are entangled and particle A has a spin-up, that means particle B will have a spin up. This means that observing what one particle will do provides an understanding of what the other will do without having to observe it.

Applications of Entanglement

Because quantum entanglement forces two particles to do the same action, it has tremendous potential in different applications. Some of these applications include superdense coding, quantum state elaboration and information exchanges through time. However, the biggest potential application is through the quantum computer. The quantum computer is made up of qubits rather than bits like the classical computer. These qubits allow for the computer to run more efficiently than a classical computer. Data can be accessed and worked on much quicker because of the qubits ability to perform more types of processes.

The above is so important because when dealing with entanglement, suddenly the qubits are doing the same thing. That means they work together without requiring as much energy and therefore, more things can get done. For example, if qubit A was typically going to do action 1 and qubit B was going to do action 0 and qubit C was going to do a superposition of these, when quantum entanglement got involved, suddenly qubits A, B and C would do either 1, 0 or a superposition of them. This would allow for a more effective process to occur.