Entanglement increases the error-correcting ability of quantum error-correcting codes

Abstract

If entanglement is available, the error-correcting ability of quantum codes can be increased. We show how to optimize the minimum distance of an entanglement-assisted quantum error-correcting (EAQEC) code, obtained by adding ebits to a regular quantum stabilizer code, over different encoding operators. By this encoding optimization procedure, we found a number of EAQEC codes, including a family of entanglement-assisted quantum repetition codes and several optimal EAQEC codes. © 2013 American Physical Society.