(3, 1)量子誤り訂正符号による擬似ベル状態の純粋化
An entanglement purification of a quasi-Bell state from (3, 1) quantum error correcting code is considered. It is shown that the fidelity between a quasi-Bell state decohered by a bit-flip channel and an ideal quasi-Bell state is improved by the purification for wide range of the bit-flip probability of the channel.