supported by the National Basic Research Program of China (Grant No.2010CB328300);the National Natural Science Foundation of China (Grant Nos.60972046 and 60902030);the Program for Changjiang Scholars and Innovative Research Team in University (Grant No.IRT0852);the Natural Science Foundation of Shaanxi Province (Grant No.2010JQ8025);the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No.20100203120004);the 111 Program (Grant No.B08038);the China Scholarship Council (Grant No.[2008]3019)
We address the problem of encoding entanglement-assisted (EA) quantum error-correcting codes (QECCs) and of the corresponding complexity. We present an iterative algorithm from which a quantum circuit composed of ...