Franson J D, Donegan M M, Fitch M J, Jacobs B C, Pittman T B
Johns Hopkins University, Applied Physics Laboratory, Laurel, Maryland 20723, USA.
Phys Rev Lett. 2002 Sep 23;89(13):137901. doi: 10.1103/PhysRevLett.89.137901. Epub 2002 Sep 4.
Knill, Laflamme, and Milburn [Nature (London) 409, 46 ((2001))]] have shown that quantum logic operations can be performed using linear optical elements and additional ancilla photons. Their approach is probabilistic in the sense that the logic devices fail to produce an output with a failure rate that scales as 1/n, where n is the number of ancilla. Here we present an alternative approach in which the logic devices always produce an output with an intrinsic error rate that scales as 1/n(2), which may have several advantages in quantum computing applications.
克尼尔、拉弗拉姆和米尔本[《自然》（伦敦）409, 46（(2001)）]已经表明，可以使用线性光学元件和额外的辅助光子来执行量子逻辑运算。他们的方法是概率性的，即逻辑器件会以1/n的故障率无法产生输出，其中n是辅助光子的数量。在这里，我们提出一种替代方法，其中逻辑器件总是以1/n²的固有错误率产生输出，这在量子计算应用中可能具有几个优势。
