Stuttgart 2012 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 25: Quanteninformation: Konzepte und Methoden 3

Q 25.3: Talk

Tuesday, March 13, 2012, 11:00–11:15, V7.01

Robustness of the two-dimensional cluster phase in an external magnetic field — •Henning Kalis, Daniel Klagges, and Kai Phillip Schmidt — Lehrstuhl für Theoretische Physik I, TU Dortmund, Germany

The cluster state represents a highly entangled state which is one central object for measurement-based quantum computing. Here we study the robustness of the cluster state on the two-dimensional square lattice at zero temperature in the presence of external magnetic fields by means of high-order series expansions. Interestingly, the phase diagram contains a self-dual line in parameter space allowing many precise statements about the fate of the cluster phase at finite fields. We provide strong evidences for first- and second-order phase transitions between the cluster phase and polarized phases.