What name is given to the loss of quantum coherence through interaction with the environment?

Quantum decoherence is the loss of quantum coherence through interaction with the environment.

A quantum superposition can maintain definite phase relationships only while the relevant system remains sufficiently isolated. Interactions with surrounding particles, fields, or measuring equipment entangle the system with its environment. When the environment is ignored, interference terms in the system’s reduced description become extremely small, making certain alternatives behave like classical possibilities.

Decoherence helps explain why macroscopic objects do not usually display visible interference, but it is not identical to wavefunction collapse. Decoherence describes the physical loss of accessible phase coherence; interpretations of quantum mechanics differ about whether an additional collapse is fundamental. The process is also a major challenge in quantum computing, where unwanted environmental interactions create errors. Quantum error correction is designed to preserve useful information despite such noise.