Quantum mechanics can reduce the complexity of classical models.

@article{Gu2012QuantumMC,
  title={Quantum mechanics can reduce the complexity of classical models.},
  author={Mile Gu and Karoline Wiesner and Elisabeth Rieper and Vlatko Vedral},
  journal={Nature communications},
  year={2012},
  volume={3},
  pages={
          762
        }
}
Mathematical models are an essential component of quantitative science. They generate predictions about the future, based on information available in the present. In the spirit of simpler is better; should two models make identical predictions, the one that requires less input is preferred. Yet, for almost all stochastic processes, even the provably optimal classical models waste information. The amount of input information they demand exceeds the amount of predictive information they output… 
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