January 2008, to be published in Physical Review A


Correlated errors can lead to better performance of quantum codes
A. Shabani

A formulation for evaluating the performance of quantum error correcting codes for a general error model is presented. In this formulation, the correlation between errors is quantified by a Hamiltonian description of the noise process. We classify correlated errors using the system-bath interaction: local vs. non-local and two-body vs. many-body. In particular, we consider CSS codes and observe a better performance in the presence of correlated errors depending on the timing of the error recovery. We also find this timing to be an important factor in the design of a coding system for achieving higher fidelities.

© 2008 The American Physical Society.