Quantum contextuality describes a form of non-classicality where the output of a quantum measurement C depends on which quantum measure, A or B, were made before -- even when A and B both commute with C and thus should each not disturb the measurement statistics of C.
This phenomenon, however, can be replicated by a classical process if it had memory, and this memory is used to remember what questions were asked before. A classical example would be locking a PhD student in a box and asking him to replicate the predictions of quantum theory. Could we then quantify how non-classical a process of seque
ntial measurements is by the amount of extra past information such a student must remember? Here we studied two iconic classes of measurements that induced quantum-contextuality. In each case, the amount of classical information needed to model the exceeded that of their respective quantum models using quantum theory.
- Optimal Classical Simulation of State-Independent Quantum Contextuality
Adán Cabello, Mile Gu, Otfried Gühne, Zhen-Peng Xu, Phys. Rev. Lett. 120, 130401
