论文标题
量子状态断层扫描通过连续使用相同信息不完整的测量设备
Quantum state tomography via sequential uses of the same informationally incomplete measuring apparatus
论文作者
论文摘要
只能通过使用$ M \ geqslant d^2 $成果进行信息完整的测量来推断出$ d $维量子系统的状态。但是，实验可访问的测量在信息上可能是不完整的。在这里，我们表明，如果连续应用多次，单个信息不完整的测量设备仍然能够提供有关量子系统的所有信息。我们为这种测量机构提供了必要且充分的条件，并为$ n $ Qubits提供了Qubits，Qutrits，Qutrits，一般$ d $级别的系统和复合系统的说明性示例，其中存在这样的测量设备。我们表明，在考虑的情况下，射影测量和吕德斯测量值没有2个结果。
State of a $d$-dimensional quantum system can only be inferred by performing an informationally complete measurement with $m\geqslant d^2$ outcomes. However, an experimentally accessible measurement can be informationally incomplete. Here we show that a single informationally incomplete measuring apparatus is still able to provide all the information about the quantum system if applied several times in a row. We derive a necessary and sufficient condition for such a measuring apparatus and give illustrative examples for qubits, qutrits, general $d$-level systems, and composite systems of $n$ qubits, where such a measuring apparatus exists. We show that projective measurements and Lüders measurements with 2 outcomes are useless in the considered scenario.
