State-independent experimental test of quantum contextuality in solid state system

TL;DR

This paper reports the first state-independent experimental test of quantum contextuality in a solid state system using a nitrogen-vacancy center in diamond at room temperature, confirming quantum mechanics over non-contextual hidden variable theories.

Contribution

It demonstrates, for the first time in a solid state system, a violation of a state-independent inequality related to quantum contextuality using a natural qutrit.

Findings

Violation of the non-contextual hidden variable inequality in a solid state system

First room-temperature demonstration of quantum contextuality in such systems

Supports the fundamental non-classical nature of quantum mechanics

Abstract

Quantum mechanics implies that not all physical properties can be simultaneously well defined, such as the momentum and position due to Heisenberg uncertainty principle. Some alternative theories have been explored, notably the non-contextual hidden variable theories in which the properties of a system have pre-defined values which are independent of the measurement contextual. However, the Kochen-Specker theorem showed that such non-contextual hidden variable theories are in conflict with quantum mechanics. Recently, a state-independent inequality satisfied by non-contextual hidden variable theories and violated by quantum mechanics is proposed in the simplest three-state system (a qutrit) by the least 13 projection measurement rays. Here, we report an experimental demonstration of the violation of this inequality. This provides a state-independent experimental test of quantum contextuality, for the first time in solid state system, by a natural qutrit of nitrogen-vacancy center in diamond at room temperature.