Shringarpure S U, Franson J D
Physics Department, University of Maryland Baltimore County, Baltimore, MD, 21250, USA.
Sci Rep. 2021 Nov 11;11(1):22067. doi: 10.1038/s41598-021-01384-2.
Knill, Laflamme, and Milburn showed that linear optics techniques could be used to implement a nonlinear sign gate. They also showed that two of their nonlinear sign gates could be combined to implement a controlled-phase gate, which has a number of practical applications. Here we describe an alternative implementation of a controlled-phase gate for a single-rail target qubit that only requires the use of a single nonlinear sign gate. This gives a much higher average probability of success when the required ancilla photons are generated using heralding techniques. This implementation of a controlled-phase gate destroys the control qubit, which is acceptable in a number of applications where the control qubit would have been destroyed in any event, such as in a postselection process.
克尼尔、拉弗拉姆和米尔本表明，线性光学技术可用于实现一个非线性符号门。他们还表明，他们的两个非线性符号门可以组合起来实现一个受控相位门，该受控相位门有许多实际应用。在这里，我们描述了一种针对单轨目标量子比特的受控相位门的替代实现方式，它只需要使用一个非线性符号门。当使用预示技术生成所需的辅助光子时，这会给出高得多的平均成功概率。这种受控相位门的实现方式会破坏控制量子比特，在许多应用中这是可以接受的，比如在一些后选择过程中，控制量子比特无论如何都会被破坏。
