金刚石氮空位色心体系的量子纠缠态制备

利用金刚石氮空位色心体系耦合于一个双边的光子晶体腔(该光子晶体腔与两个波导耦合)来制备Bell态、GHZ态和团簇态。当光子被探测和进行幺正操作后,就得到纠缠态。同时计算了该体系的保真度,发现在近似参数条件下,该模型可得到较好结果。     

Direct measurement of two-qubit phononic entangled states via optomechanical interactions

We propose schemes of direct concurrence measurement for two-qubit phononic states from quantized mechanical vibration. By combining the Mach-Zehnder interferometer with the optomechanical cross-Kerr nonlinear effect, direct concurrence measurement schemes for two-qubit phononic entangled states are achieved with the help of photon detection with respect to the output of the interferometer. For different types of entangled states, diversified quantum devices and operations are designed accordingly. The final analysis shows reasonable performance under the current parameter conditions. Our schemes may be useful for potential phonon-based quantum computation and information in the future.     

基于囚禁在双边光学微腔内的量子点自旋辅助的自避错纠缠浓缩

利用囚禁在双边光学微腔内的量子点自旋的辅助,我们提出了一个对于未知较少纠缠态的纠缠浓缩协议。该方案利用了自避错机制来克服局域计算错误,它对于实验缺陷具有内禀的鲁棒性。我们讨论了这个纠缠浓缩协议在当前实验参数下的表现,结果表明这个方案单次执行成功概率可以达到45%。这个纠缠浓缩协议可以作为一个对未来的量子通信和量子网络具有前景的基础构件。