Advantages of nonclassical pointer states in postselected weak measurements
Advantages of nonclassical pointer states in postselected weak measurements
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DOI：
10.1103/physreva.92.022109
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发表时间：
2015-08-11
影响因子：
2.9
通讯作者：
Al-Amri, M.
中科院分区：
文献类型：
--
作者：
Turek, Yusuf;Maimaiti, W.;Al-Amri, M.
在弱测量理论下，我们研究了相干态、压缩真空态和薛定谔猫态的非经典指针态相对于半经典指针态的优势。这些状态被用作系统操作员(A)覆盖盖的指针状态，其中属性(A)覆盖盖(2)=(I)覆盖盖，其中(I)覆盖盖表示身份运算符。我们计算了非后选择弱测量和后选择弱测量的信噪比。后者被用来寻找上述指针态的量子Fisher信息。详细研究了具有任意相互作用强度的指针态的平均位移。一个关键的结果是，我们发现非经典指针态的后选择弱测量方案优于半经典方案。这可以提高测量过程的精度。
We investigate, within the weak measurement theory, the advantages of nonclassical pointer states over semiclassical ones for coherent, squeezed vacuum, and Schrodinger cat states. These states are utilized as pointer states for the system operator (A) over cap with property (A) over cap (2) = (I) over cap, where (I) over cap represents the identity operator. We calculate the ratio between the signal-to-noise ratio of nonpostselected and postselected weak measurements. The latter is used to find the quantum Fisher information for the above pointer states. The average shifts for those pointer states with arbitrary interaction strength are investigated in detail. One key result is that we find the postselected weak measurement scheme for nonclassical pointer states to be superior to semiclassical ones. This can improve the precision of the measurement process.