Decoherenciája

Decoherenciája is a concept in quantum mechanics that describes the process by which a quantum system loses its quantum properties, such as superposition and entanglement, and begins to behave like a classical system. This loss of quantum coherence is driven by the interaction of the quantum system with its environment. When a quantum system interacts with many degrees of freedom in its surroundings, the quantum information that defines the system's state becomes spread out and essentially inaccessible to the system itself.

Think of a quantum particle in a superposition of two locations. As it interacts with the air molecules, photons, or any other part of its environment, these interactions effectively "measure" the particle's position. Each interaction causes the quantum state to become correlated with the state of the environment. Over time, these correlations become so complex and widespread that it becomes impossible to observe the original superposition. The quantum system appears to collapse into a single, definite state, as if a classical measurement had been made.

Decoherence is a crucial phenomenon for understanding the transition from the quantum realm to the classical world we experience. It explains why we don't observe macroscopic objects in superposition states. While the underlying quantum mechanics remains, the extreme sensitivity of quantum states to environmental interactions makes quantum effects practically unobservable at everyday scales. It is a key challenge in the development of quantum computers, as unwanted decoherence can destroy the delicate quantum states required for computation.