Acknowledgement

The authors thank Dr. Martin Hecht and Frank Huber for technical assistance. They are grateful to Sim-Tech (Forschungszentrum für Simulationstechnik) for computing resources and financial support.

Authors:	R. Hilfer and Th. Zauner
originally published in:	Physical Review Letters E, Vol. 84, 062301 (2011)
originally submitted:	July 26th, 2011