论文标题
使用时间三个方向的形式主义探索选择后引起的量子现象
Exploring postselection-induced quantum phenomena with time-bidirectional state formalism
论文作者
论文摘要
在这里，我们介绍了以一般方式统一的时间差异状态形式主义（TBSF），标准量子机械形式主义没有选择后和时间 - 对称性的两态（密度）矢量形式主义，该形式与后选择的状态有关。在提出的方法中，量子粒子的状态称为时间双向状态，等于在相反的时间方向上传播的两个粒子的连接状态。对于一般的时差状态，我们得出了广义测量结果的结果概率，以及遗传学可观察物的平均值和弱价值。我们还展示了在没有选择后和广义的两态（密度）向量的特殊情况下，所获得的表达方式如何减少到已知的表达式。然后，我们基于相互无偏基的基础和对称的信息完全正面操作员评估度量制定层析成像协议，从而实验了一个未知的单个量子量表时间三方向状态。最后，我们采用开发的技术在量子传送协议中跟踪Qubit的时间反转旅程，该协议以云访问的噪声超导量子处理器实现。所获得的结果证明存在选择后引起的Qubit的适当时间箭头，该箭头与经典观察者的时间箭头不同，并证明了TBSF的能力探索在噪声存在下被选中带来的量子现象。
Here we present the time-bidirectional state formalism (TBSF) unifying in a general manner the standard quantum mechanical formalism with no postselection and the time-symmetrized two-state (density) vector formalism, which deals with postselected states. In the proposed approach, a quantum particle's state, called a time-bidirectional state, is equivalent to a joined state of two particles propagating in opposite time directions. For a general time-bidirectional state, we derive outcome probabilities of generalized measurements, as well as mean and weak values of Hermitian observables. We also show how the obtained expressions reduce to known ones in the special cases of no postselection and generalized two-state (density) vectors. Then we develop tomography protocols based on mutually unbiased bases and a symmetric informationally complete positive operator-valued measure, allowing experimental reconstruction of an unknown single qubit time-bidirectional state. Finally, we employ the developed techniques for tracking of a qubit's time-reversal journey in a quantum teleportation protocol realized with a cloud-accessible noisy superconducting quantum processor. The obtained results justify an existence of a postselection-induced qubit's proper time-arrow, which is different from the time-arrow of a classical observer, and demonstrate capabilities of the TBSF for exploring quantum phenomena brought forth by a postselection in the presence of noise.
