Iterative Optimization of Quantum Error Correcting Codes

M. Reimpell, R. F. Werner

Published 2003-07-19, updated 2005-05-11Version 2

We introduce a convergent iterative algorithm for finding the optimal coding and decoding operations for an arbitrary noisy quantum channel. This algorithm does not require any error syndrome to be corrected completely, and hence also finds codes outside the usual Knill-Laflamme definition of error correcting codes. The iteration is shown to improve the figure of merit "channel fidelity" in every step.