ITP-quantumseminare

itp-quantumseminare@lists.phys.ethz.ch

March 2009

4 participants
12 discussions

additional talk this week
by Roger Colbeck 02 Mar '09

02 Mar '09

Dear all, This week there will be an additional talk by one of our master's students, Junji Shimagaki this Friday 5-6pm in HIT J51 (note unusual room). Title and abstract are below. Cheers, Roger --- Numerical analysis of the stability of toric code against errors We studied the error tolerance of toric codes in the presence of coupling with the environment. The errors are not removable but can be corrected under a certain amount of qubit error population. However, the exact algorithm to correct them perfectly in a short time is not a trivial problem. Hence one may have to introduce heuristic algorithms if the problem becomes too big to solve exactly. According to the previous study by Dennis E. et al., the approach to the problem of toric codes can be mapped onto that of spin glasses one by one, although the forms of their hamiltonians are different. Our research shows the equivalency and the non-equivalency between the system of toric codes and spin glasses from the point of view of statistical physics. At the end, we clarify the independency of size in terms of tolerance as long as the size is big enough and the substantial change of the threshold value in different types of error models. Also we show the phase transition from an error non-correctable to correctable region as a function of the error rate. The presentation will give a short overview of error correction to make it accessible to people who are unfamiliar with these themes.

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[QI] QI Seminar
by Dejan D. Dukaric 02 Mar '09

02 Mar '09

Dear All, This weeks research day on Tuesday will be at the Computer Science Building. Barbara Keller will present her Master Thesis. Speaker: Barbara Keller Title: An Analysis of the Parallel CHSH Game Time: 5 pm Place: IFW D42 Abstract: The CHSH game is a special case of interactive proof systems, whose theory played an important role in the area of cryptography and computational complexity. This talk presents the game and gives an overview over the so far known results. Cheers, Dejan

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