  We study the performance of simple quantum error correcting codes with
respect to correlated noise errors characterized by a finite correlation
strength. Specifically, we consider bit flip (phase flip) noisy quantum memory
channels and use repetition and noiseless quantum codes. We characterize the
performance of the codes by means of the entanglement fidelity as function of
the error probability and degree of memory. Finally, comparing the entanglement
fidelities of repetition and noiseless quantum codes, we find a threshold for
the correlation strength that allows to select the code with better
performance.
