Quantum entanglement is a phenomenon that occurs in the realm of quantum physics, where two or more particles become connected in such a way that their properties become correlated, regardless of the distance between them. It's like having a pair of magical coins that are forever linked, no matter how far apart they are.
Imagine you have two particles, let's call them Particle A and Particle B. When these particles are entangled, their properties, such as their spin or polarization, become linked together. This means that if you measure the spin of Particle A, for example, the measurement outcome will instantly affect the spin of Particle B, even if it's located far away.
The remarkable aspect of entanglement is that the state of the entangled particles is described by a single quantum wavefunction, which represents all the possible combinations of their properties. However, when you measure one of the entangled particles, the wavefunction "collapses" into a specific state, and as a result, the state of the other particle also collapses to a correlated value.
To better grasp the concept, let's consider an analogy with two entangled coins. Imagine you have two coins that are entangled in a way that if one shows heads, the other will always show tails, and vice versa. If you separate the coins and flip one of them, you instantly know the outcome of the other coin, regardless of the distance between them.
Quantum entanglement is a fascinating and counterintuitive phenomenon that defies classical intuition. It has been experimentally observed and plays a crucial role in various quantum technologies, such as quantum cryptography and quantum teleportation. It also forms the basis for studying quantum mechanics and understanding the peculiarities of the quantum world.