Quantum theory has been successfully validated in numerous laboratory experiments. But
would such a theory, which effectively describes the behavior of microscopic physical …

In principle, quantum key distribution (QKD) offers information-theoretic security based on
the laws of physics. In practice, however, the imperfections of realistic devices might …

Bell's 1964 theorem, which states that the predictions of quantum theory cannot be
accounted for by any local theory, represents one of the most profound developments in the …

Entangled quantum states are not separable, regardless of the spatial separation of their
components. This is a manifestation of an aspect of quantum mechanics known as quantum …

After they have interacted, quantum particles generally behave as a single nonseparable
entangled system. The concept of entanglement plays an essential role in quantum physics …

How can one prove that a given quantum state is entangled? In this paper we review
different methods that have been proposed for entanglement detection. We first explain the …

The superposition principle plays the most central role in all considerations of quantum
information, and in most of the" gedanken" experiments and even the paradoxes of quantum …

We summarize important recent advances in quantum metrology, in connection to
experiments in cold gases, trapped cold atoms and photons. First we review simple …

Entangled-photon sources with simultaneously near-unity heralding efficiency and
indistinguishability are the fundamental elements for scalable photonic quantum …

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