Howell JC, Yeazell JA
Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Phys Rev Lett. 2000 Jul 3;85(1):198-201. doi: 10.1103/PhysRevLett.85.198.
Single-photon interferometry has been used to simulate quantum computations. Its use has been limited to studying few-bit applications due to rapid growth in physical size with numbers of bits. We propose a hybrid approach that employs n photons, each having L degrees of freedom yielding L(n) basis states. The photons are entangled via a quantum nondemolition measurement. This approach introduces the essential element of quantum computing, that is, entanglement into the interferometry. Using these techniques, we demonstrate a controlled-NOT gate and a Grover's search circuit. These ideas are also applicable to the study of nonlocal correlations in many dimensions.
单光子干涉测量法已被用于模拟量子计算。由于其物理尺寸会随着比特数的增加而迅速增大，其应用一直局限于研究少比特的情况。我们提出了一种混合方法，该方法采用n个光子，每个光子具有L个自由度，从而产生L(n)个基态。这些光子通过量子无损测量实现纠缠。这种方法将量子计算的基本要素，即纠缠引入到干涉测量中。利用这些技术，我们演示了一个受控非门和一个格罗弗搜索电路。这些想法也适用于研究多维度的非局域关联。
