论文标题
实验性下限量量子通道的经典能力
Experimental Lower Bounds to the Classical Capacity of Quantum Channels
论文作者
论文摘要
我们展示了一个实验程序，以证明嘈杂量子通道的经典能力。该方法利用了固定的两分纠缠状态，在该状态下将系统值发送到通道输入和本地测量集$σ_{x} \otimesσ_{x} $，$σ_{y} \ outimes \ outimes = _ {Y} {Y} $ {Y} $ and $σ_{z} = {z} = z {z {z} $} Qubit，因此不诉诸于完整的量子过程断层扫描。然后，通过重建条件概率，噪声反卷积和有关相互信息的经典优化来实现经典能力的见证。通过在Pauli通道和振幅阻尼通道中的两光子极化状态来测试该方法为经典能力提供下限的方法。测得的与通道的下限与模拟数据高度一致，这些数据都考虑到了输入状态的实验纠缠保真度$ f = 0.979 \ pm 0.011 $ and pm pm 0.011 $。
We show an experimental procedure to certify the classical capacity for noisy qubit channels. The method makes use of a fixed bipartite entangled state, where the system qubit is sent to the channel input and the set of local measurements $σ_{x}\otimesσ_{x}$, $σ_{y}\otimesσ_{y}$ and $σ_{z}\otimesσ_{z}$ is performed at the channel output and the ancilla qubit, thus without resorting to full quantum process tomography. The witness to the classical capacity is then achieved by reconstructing sets of conditional probabilities, noise deconvolution, and classical optimization of the pertaining mutual information. The performance of the method to provide lower bounds to the classical capacity is tested by a two-photon polarization entangled state in Pauli channels and amplitude damping channels. The measured lower bounds to the channels are in high agreement with the simulated data, which take into account both the experimental entanglement fidelity $F=0.979\pm 0.011$ of the input state and the systematic experimental imperfections.
