Sudden death of quantum advantage in correlation generations

Quantum noise is one of the most profound obstacles to implementing large-scale quantum algorithms and schemes. In particular, the dynamical process by which quantum noise, varying in strength from 0 to critical levels, affects and destroys quantum advantage has not been well understood. Meanwhile, correlation generation serves as a precious theoretical model for information processing tasks, where quantum advantage can be precisely quantified. In this study, we show that this model provides valuable insights into the understanding of this dynamical process. We prove that, as the strength of quantum noise continuously increases from 0, the quantum advantage diminishes gradually and eventually vanishes. Unexpectedly, in some cases, we observe the phenomenon of a sudden death of quantum advantage: When the noise strength exceeds a certain threshold, the quantum advantage abruptly disappears from a substantial level. This phenomenon, once again, reveals the tremendous impact of noise on quantum information processing tasks.