Dear all

Please be informed about the following QSIT Seminar.

With best regards, Ilona Blatter ------------------------------------------------------------------------------------------------------ Date: Monday November 8, 2010 Time: 41:00 Place: HIT H 42 Host: Atac Imamoglu

Bringing order through disorder: Localization in the toric code James Wootton University of Leeds, UK

Anderson localization emerges in quantum systems when randomised parameters cause the exponential suppression of motion. In this talk we will consider the localisation phenomenon in the toric code and its ability to sustain quantum information in a fault tolerant way. First we will show that, in the presence of a magnetic field, the existence of a single anyon pair destroys logical information in a time linear with the system size. However, once the disorder, inherent in any physical realisation of the code, is taken into account, it allows the tolerable density of anyons to remain finite as the localisation effect takes place. Enhancements to this effect are also considered using random lattices.

------------------------------------------------------------------------------------------------------ ETH Zurich Dr. Ilona Blatter QSIT Coordinator Laboratory for Solid State Physics HPF E 13 Schafmattstrasse 16 8093 Zurich

ilona.blatter@phys.ethz.ch www.qsit.ethz.ch

Phone: +41 44 633 36 06 Home: +41 44 844 42 50