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.