Quantum Phase Transitions in a Linear Ion Trap

We show that the quantum phase transition of the Tavis-Cummings model can be realised in a linear ion trap of the kind proposed for quantum computation. The Tavis-Cummings model describes the interaction between a bosonic degree of freedom and a collective spin. In an ion trap, the collective spin system is a symmetrised state of the internal electronic states of N ions, while the bosonic system is the vibrational degree of freedom of the centre of mass mode for the ions.Comment: 6 pages and 2 figures. submitted to Dan Walls Memorial Volume, edited by H. Carmichael, R. Glauber, and M. Scully, to be published by Springe

Observer dependent entanglement

Understanding the observer-dependent nature of quantum entanglement has been a central question in relativistic quantum information. In this paper we will review key results on relativistic entanglement in flat and curved spacetime and discuss recent work which shows that motion and gravity have observable effects on entanglement between localized systems.Comment: Ivette Fuentes previously published as Ivette Fuentes-Guridi and Ivette Fuentes-Schulle