Colloquium: Ken Brown

Error Models and Error Thresholds

Ken Brown, Georgia Tech

The error threshold for fault-tolerant quantum computation depends
strongly on the error model.  Most calculations assume a depolarizing
model, which allows for efficient calculations based on random
applications of Pauli errors.  We have been exploring how the
threshold changes for both non-unital and coherent operations.  I will
present our results based on exact calculations of the Steane code
pseudothreshold for different error models. I will also discuss
whether the two-qubit depolarizing error model is an appropriate model
for realistic two-qubit gates and how realistic models can lead to
simpler fault-tolerant constructions.