论文标题
通过弱测量来保护未知的量子
Protecting an unknown qubit state by weak measurement
论文作者
论文摘要
已经研究了通过弱测量结果与振幅阻尼通道和特定输入状态打击去脱糖性的问题。我们将其推广到一个大型四参数Qubit通道家族，并使所有纯净状态的平均忠诚度。作为一个副产品，我们对具有一个不变状态的所有量子通道进行了分类，并表明这些通道的参数歧管是同构成$ s^2 \ times s^1 \ times s^1 \ times s^1 $，并且包含许多有趣的通道子类。我们使用的优点是通过调整弱测量参数，在某些情况下，我们显示的平均输入输出保真度可以增加到$ 30 $。
The problem of combating de-coherence by weak measurements has already been studied for the amplitude damping channel and for specific input states. We generalize this to a large four-parameter family of qubit channels and for the average fidelity over all pure states. As a by-product we classify all the qubit channels which have one invariant pure state and show that the parameter manifold of these channels is isomorphic to $S^2\times S^1\times S^1$ and contains many interesting subclasses of channels. The figure of merit that we use is the average input-output fidelity which we show can be increased up to $30$ percents in some cases, by tuning of the weak measurement parameter.
