Quantum measurements and engineering of interactions for quantum simulations with trapped ions
Dr. Christian Roos (Institut für Quantenoptik und Quanteninformation, Innsbruck)

<p> Coupling internal and vibrational states of a string of trapped ions has proven to be an effective way of entangling the ions' internal states. In recent experiments, we have used this mechanism for the demonstration of high-fidelity quantum gates [1], QND measurements of spin correlations [2] and creation of large entangled states. However, these interactions are also of interest for the purpose of quantum simulations where the motional state no longer acts as an auxiallary quantum system only [3]. In this talk, I will focus on an experiment where a laser-cooled trapped ion is set to behave as a free relativistic quantum particle. This nicely demonstrates that a system acting as a quantum simulator may have completely different physical properties than the quantum system to be simulated. In this way, the dynamics associated with relativistic effects like 'Zitterbewegung' and Klein tunneling can be investigated with a string of laser-cooled ions. I will discuss how to engineer the necessary interactions and how to carry out measurements of observables of interest. <p>

<p> [1] J. Benhelm et al., Nature Physics 4, 463 (2008). <p>

<p> [2] G. Kirchmair et al., Nature 460, 494 (2009). <p>

<p> [3] R. Gerritsma et al., Nature 463, 68 (2010). <p>