[devodo]

This is not true. For example, Mermin's device cannot be done using classical physics regardless of running time. https://en.wikipedia.org/wiki/Mermin%27s_device

[deepburner]

The first reference in the article you linked is titled "Computer simulation of Mermin's quantum device".

[devodo]

The paper is saying that attempting to simulate the device in code is a valuable lesson to students for precisely the reason that it cannot be done (correctly), thereby illustrating the limits of classical computation.

> In the current paper, we make use of the recently published work in quantum information theory by Candela to have students write code to simulate the operation of the device in that article. Analysis of the device has significant pedagogical value—a fact recognized by Feynman—and simulation of its operation provides students a unique window into quantum mechanics without prior knowledge of the theory.