How Quantum Contextuality disappears in the Classical Limit

The interaction between a quantum system and its environment is the primary driver of classicality, with foundational open-system approaches like the Caldeira-Leggett model effectively capturing the resulting macroscopic effects, such as quantum dissipation and decoherence¹. As the quantum system engages with its environment, quantum contextuality gradually disappears, giving rise to classical behavior. This phenomenon is crucial in understanding the transition from quantum to classical systems. The Caldeira-Leggett model, in particular, has been instrumental in shedding light on this process, providing valuable insights into the emergence of classicality. However, a more precise definition of classicality and quantumness is still needed to fully comprehend this transition. The disappearance of quantum contextuality in the classical limit has significant implications for the development of quantum technologies, as it highlights the challenges of maintaining quantum coherence in large-scale systems. This understanding is essential for practitioners working on quantum computing and quantum information processing systems, as it directly affects the design and implementation of these systems.