quantenverschränkten

Quantum entanglement, often referred to as "quantenverschränkung" in German, is a fundamental phenomenon in quantum physics where two or more particles become inextricably linked, such that the state of one particle instantaneously influences the state of the other(s), regardless of the distance separating them. This effect was first described by Albert Einstein, Boris Podolsky, and Nathan Rosen in 1935 in what is now known as the EPR paradox, where they questioned the completeness of quantum mechanics due to what they perceived as "spooky action at a distance." Later, John Stewart Bell developed mathematical inequalities to test whether quantum mechanics could truly produce such correlations, which experiments have since confirmed.

The key feature of quantum entanglement is that measuring one particle in an entangled pair (or larger group) determines the state of its partner(s) immediately, even if they are light-years apart. This correlation cannot be explained by classical physics, where information can only travel at the speed of light. Entanglement is not a violation of relativity because no information is transmitted faster than light—only the pre-existing quantum state is revealed upon measurement.

Quantum entanglement plays a crucial role in quantum computing, cryptography, and teleportation protocols. For example, quantum key distribution (QKD) leverages entanglement to create secure communication channels, as any eavesdropping attempt would disturb the quantum states, alerting legitimate users. Additionally, entanglement enables quantum teleportation, where the state of a particle is transmitted using entangled pairs and classical communication.

Despite its counterintuitive nature, quantum entanglement has been experimentally verified in various forms, including photon pairs, electrons, and even larger systems. It remains a cornerstone of quantum theory, challenging classical intuitions while enabling cutting-edge technological advancements.