Quantum entanglement is a phenomenon in which two or more particles become correlated in such a way that the state of one particle cannot be described independently of the state of the other(s). When particles are entangled, their properties become interdependent, regardless of the distance between them. This unique correlation has been experimentally verified and is a fundamental aspect of quantum mechanics.
While quantum entanglement itself does not directly cause particles to take action or transmit information faster than the speed of light, it can play a role in certain phenomena. Here are a couple of examples:
Quantum Teleportation: Quantum entanglement is a crucial ingredient in quantum teleportation, a process by which the state of a quantum system can be transmitted from one location to another without physically moving the system itself. In quantum teleportation, an entangled pair of particles, often referred to as a Bell pair, is created and shared between two distant parties, Alice and Bob. When Alice wants to teleport the state of a particle to Bob, she performs measurements on her particle and transmits the measurement results to Bob using classical communication. By utilizing the entangled pair and the measurement results, Bob can reconstruct the original state on his end. It's important to note that this process does not involve transmitting the actual quantum state itself but rather the information needed to recreate it.
Quantum Correlations: Entangled particles can exhibit correlations that are stronger than what can be explained by classical physics. For example, if two entangled particles are measured, the outcomes of those measurements will be correlated, even if the measurements are performed far apart. However, these correlations cannot be exploited to transmit information faster than the speed of light. The measurement outcomes on each end of the entangled system appear random and cannot be used to communicate information instantaneously.
It's worth emphasizing that while entanglement enables interesting phenomena, it does not allow for faster-than-light communication or violate causality. The transmission of information using entangled particles requires classical communication to complete the process. Moreover, the exact nature and interpretation of quantum entanglement continue to be topics of active scientific research and debate.