Häviökoherenssi

Häviökoherenssi, known in English as lossy decoherence, is a phenomenon in quantum mechanics that describes the process where a quantum system loses its coherence due to interactions with its environment. Unlike standard decoherence, which focuses on the loss of quantum superposition, häviökoherenssi specifically refers to the degradation of the system's ability to maintain a coherent quantum state when there's an irreversible exchange of energy or particles with the environment. This exchange leads to a net loss of information from the system into the environment, effectively "dissipating" quantum properties.

The term is particularly relevant in contexts involving energy transfer, such as in quantum thermodynamics or when studying open quantum systems. When a quantum system interacts with a larger, hotter environment, energy can flow from the system to the environment, or vice versa. This energy exchange can perturb the delicate quantum correlations within the system, causing its quantum state to become more classical-like. Häviökoherenssi highlights that this environmental interaction is not merely passive observation but an active process of energy and information transfer that fundamentally alters the system's quantum nature. It is a crucial concept for understanding the transition from quantum to classical behavior and for designing quantum technologies that are robust against environmental noise.