What is the concept of decoherence?

Decoherence is a phenomenon in quantum mechanics whereby a system’s quantum coherence is lost or destroyed due to interactions with its environment, leading to the emergence of classical behavior. In decoherence, the phase relationships between the quantum states of a system become scrambled, resulting in the suppression of interference effects and the appearance of classical-like behavior at the macroscopic scale. Decoherence poses challenges for maintaining quantum coherence in quantum computing and other quantum technologies.