Error models and error thresholds - Ken Brown

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. Finally, I will conclude with our recent implementation of a quantum error detection code using trapped ions in collaboration with the University of Maryland.