Entanglement is a phenomenon in quantum mechanics where two or more particles become connected in such a way that the state of one particle can affect the state of the other, no matter how far apart they are. This means that if one particle is measured or observed, the other particle will immediately have its state determined, regardless of the distance between them.
Entanglement has been used in various practical applications such as quantum computing, quantum cryptography, and quantum teleportation. It also plays a crucial role in research on quantum entanglement and its potential for quantum communication and computing technologies.
While entanglement itself cannot be observed directly, its effects can be measured and observed through experiments. These experiments involve measuring the correlation between the states of the entangled particles, which can provide evidence of entanglement.
Entanglement is closely related to the concept of superposition, which is the ability of a quantum system to exist in multiple states simultaneously. In entanglement, the particles are in a superposition of states, and when one particle's state is measured, it collapses the superposition and determines the state of the other particle.
While entanglement was first proposed as a theoretical concept, it has been extensively studied and demonstrated through experiments. The phenomenon has been proven to exist in various systems and is now a well-accepted principle in quantum mechanics.