Testing the Kochen-Specker theorem with Josephson qubits

TL;DR

This paper proposes an experimental method using superconducting Josephson qubits to macroscopically test the Kochen-Specker theorem, highlighting quantum contextuality versus hidden-variable theories.

Contribution

It introduces a novel experimental setup with coupled Josephson qubits and measurement techniques to test quantum contextuality at a macroscopic scale.

Findings

Demonstrates controllable coupling of two Josephson charge qubits

Proposes a measurement approach to test quantum contextuality

Shows potential to verify the Kochen-Specker theorem experimentally at a macroscopic level

Abstract

We propose an experimental approach to {\it macro}scopically test the Kochen-Specker theorem (KST) with superconducting qubits. This theorem, which has been experimentally tested with single photons or neutrons, concerns the conflict between the contextuality of quantum mechnaics (QM) and the noncontextuality of hidden-variable theories (HVTs). We first show that two Josephson charge qubits can be controllably coupled by using a two-level data bus produced by a Josephson phase qubit. Next, by introducing an approach to perform the expected joint quantum measurements of two separated Josephson qubits, we show that the proposed quantum circuits could demonstrate quantum contextuality by testing the KST at a macroscopic level.