Improving the efficiency of decoding quantum error correction code

To improve the efficiency of the encoding and the decoding is the important problem in the quantum error correction. In a preceding work, a general algorithm for decoding the stabilizer code is shown. This paper will show an decoding which is more efficient for some codes. The proposed decoding as well as the conventional decoding consists of the eigenvalue output step and the entanglement dissolution step. The proposed decoding outputs a part of the eigenvalues into a part of the code qubits in contrast to the conventional method's outputting into the ancilla. Besides, the proposed decoding dissolves a part of the entanglement in the eigenvalue output step in contrast to the conventional method which does not dissolve in the eigenvalue output step. With these improvements, the number of gates was reduced for some codes.