Entangled quantum states of atomic systems

The current status of studies in the physics of entangled states of atomic systems - an interdisciplinary field involving quantum optics, quantum information, and the foundations of quantum mechanics - is reviewed. In the first part of the review, an introduction to the theory of entangled states is given, their properties and applications are described. In the second part, experiments on the creation and detection of entangled states in atomic systems are discussed along with associated experimental proposals for their refinement. Today's most advanced experimental technique for creating entangled ion states in an ion trap is considered, and promising methods focussed on the analogous states of neutral atoms are analyzed.