Liu Ye-Chao, Shang Jiangwei, Zhang Xiangdong
Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Physics, Beijing Institute of Technology, Beijing 100081, China.
Entropy (Basel). 2019 Mar 7;21(3):260. doi: 10.3390/e21030260.
Besides the superior efficiency compared to their classical counterparts, quantum algorithms known so far are basically task-dependent, and scarcely any common features are shared between them. In this work, however, we show that the depletion of quantum coherence turns out to be a common phenomenon in these algorithms. For all the quantum algorithms that we investigated, including Grover's algorithm, Deutsch-Jozsa algorithm, and Shor's algorithm, quantum coherence of the system states reduces to the minimum along with the successful execution of the respective processes. Notably, a similar conclusion cannot be drawn using other quantitative measures such as quantum entanglement. Thus, we expect that coherence depletion as a common feature can be useful for devising new quantum algorithms in the future.
除了比传统算法具有更高的效率外，目前已知的量子算法基本上都依赖于任务，它们之间几乎没有任何共同特征。然而，在这项工作中，我们表明量子相干性的耗尽在这些算法中是一种普遍现象。对于我们研究的所有量子算法，包括格罗弗算法、德乌施-约扎算法和肖尔算法，系统状态的量子相干性随着各自过程的成功执行而降至最低。值得注意的是，使用其他定量度量（如量子纠缠）无法得出类似的结论。因此，我们预计相干性耗尽作为一个共同特征，在未来设计新的量子算法时可能会很有用。
