A central result in the foundations of quantum mechanics is the Kochen-Specker theorem. In
short, it states that quantum mechanics is in conflict with classical models in which the result …

Multiphoton interference reveals strictly nonclassical phenomena. Its applications range
from fundamental tests of quantum mechanics to photonic quantum information processing …

'Der Kopf, so gesehen, hat mit dem Kopf, so gesehen, auch nicht die leiseste Ahnlichkeit (...)
Der Aspektwechsel.“Du würdest doch sagen, dass sich das Bild jetzt gänzlich geändert hat!” …

We show that there are Bell-type inequalities for noncontextual theories that are violated by
any quantum state. One of these inequalities between the correlations of compatible …

Quantum Mechanics (QM) is one of the pillars of modern physics: an impressive amount of
experiments have confirmed this theory and many technological applications are based on …

The question of whether quantum phenomena can be explained by classical models with
hidden variables is the subject of a long-lasting debate,. In 1964, Bell showed that certain …

In contrast to classical physics, quantum theory demands that not all properties can be
simultaneously well defined; the Heisenberg uncertainty principle is a manifestation of this …

This article presents a general discussion of several aspects of our present understanding of
quantum mechanics. The emphasis is put on the very special correlations that this theory …

Quantum contextuality, as proved by Kochen and Specker, and also by Bell, should manifest
itself in any state in any system with more than two distinguishable states and recently has …

We present an experimental state-independent violation of an inequality for noncontextual
theories on single particles. We show that 20 different single-photon states violate an …