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 particle, even when they are physically separated. The concept of entanglement has been experimentally verified and is a fundamental aspect of quantum mechanics.
In a quantum entangled system, the properties of the entangled particles are linked in a way that the state of one particle is dependent on the state of the other, regardless of the distance between them. This means that when a measurement is performed on one particle and its state is determined, the state of the other particle is instantaneously known, even if they are separated by vast distances. This behavior is often referred to as "spooky action at a distance," as it seems to violate classical notions of causality.
However, it is important to note that quantum entanglement does not imply that the entangled particles are physically connected or constitute opposite ends of a single particle. They can be separate entities that have become correlated through a previous interaction or a common origin. The entanglement arises due to the quantum nature of the particles and the mathematical formalism of quantum mechanics.
Various experiments and theoretical analyses have been conducted to study and understand quantum entanglement, and it is a subject of ongoing research and exploration. While the phenomenon is mysterious and counterintuitive, it is well-supported by experimental evidence and plays a significant role in various areas of quantum physics, including quantum information processing and quantum communication.