A demonstration of contextuality using quantum computers

Abstract

Open-access, online quantum computers have shown significant improvements in the past decade. Although they still suffer from noise and scalability limitations, they do offer the possibility of experimenting with quantum circuits which would otherwise have required laboratory resources and prowesses beyond the reach of most students (and even researchers). In view of this, we revisit from the ground up the notion of contextuality and show that it can now be easily demonstrated on one of the IBM quantum computers. We showcase this with an implementation of the Peres-Mermin square which, despite the high error rates, manages to violate noncontextuality by almost 28 standard deviations.

Exploiting finite geometries for better quantum advantages in Mermin-like games

“…This is a slick demonstration of the Bell-KS theorem, showing that you cannot deterministically apply hidden variables (pre-measurement operator values) to certain operator arrangements in a consistent and context-independent manner. The implementation of this game, as well as testing KS contextuality in other ways, on noisy quantum computers has been shown in [12][13][14][15].…”

“…Theorem 4.1. The classical bounds for the eloily games are 13 15 for the 2-player game E 2 and 11 15 for the 4 -player game E 4 .…”