用无退相干子空间的方法抑制集体退相干,实现不受比特反转错 误影响的通用量子计算。 该方案基于腔电动力学系统,用囚禁于腔中的2个相邻原子编码1个逻辑比特,构造出抑制集体比特 反转错误的4维无退相干子空间。通过调节外加光场与腔的耦合,在无退相干子空间中完成了2个非 对易的单比特操作和控制相位门,实现了克服集体比特反转错误的通用量子计算。

Universal quantum computation overcoming influnce of bit-flip error is realized by suppressing collective decoherence with decoherence-free subspace method. The scheme is based on cavity QED system. A logical bit is encoded by two adjacent atoms trapped in a cavity, and a four-dimensional decoherence-free subspace is constructed to suppress the collective bit reversal error. By adjusting the coupling between the external optical field and cavity, two noncommutative single-qubit operations and a controlled phase gate are implemented in decoherence-free subspace. Universal quantum computation overcoming the collective bit reversal error is realized.