Quantum entanglement is a phenomenon in quantum mechanics where two or more particles become interconnected in such a way that the state of one particle is instantly correlated with the state of the other particles, regardless of the distance between them. It is a fundamental aspect of quantum theory, and while it may seem counterintuitive, it has been extensively experimentally verified.
To understand how quantum entanglement works, we need to delve into the principles of quantum mechanics. In the quantum world, particles such as electrons, photons, or atoms do not have definite properties until they are measured. Instead, they exist in a superposition of multiple states, meaning they can be in multiple states simultaneously. This concept is described by a mathematical framework called wave functions.
When two particles interact or are generated together, their wave functions can become entangled. This means that their individual states are no longer independent but are intrinsically linked. The entangled particles are described by a joint wave function that encompasses the possible states of both particles.
The remarkable aspect of entanglement is that when one of the entangled particles is measured and its state is determined, the state of the other particle becomes instantly correlated, regardless of the distance between them. This correlation is instantaneous, even if the particles are separated by vast distances.
This behavior has been confirmed through various experiments, such as the Bell tests, where the measurements of entangled particles have consistently violated certain inequalities, indicating that they cannot be explained by classical physics or local hidden variables.
While the exact mechanism behind quantum entanglement is still a topic of ongoing research and debate, it is an established phenomenon in quantum mechanics. It challenges our classical intuitions because it defies our notions of locality and separability, but it has been extensively tested and verified through experiments. Quantum entanglement is also the foundation of various applications, including quantum computing, quantum cryptography, and quantum teleportation.