Quantum Technologies Center, Faculty of Physics, Lomonosov Moscow State University, Leninskie gory 1, building 35, Moscow 119991, Russia.
Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary Prospect, 7a, Moscow 117312, Russia.
Phys Rev Lett. 2020 Jan 10;124(1):010501. doi: 10.1103/PhysRevLett.124.010501.
The decomposition of large unitary matrices into smaller ones is important because it provides ways to the realization of classical and quantum information processing schemes. Today, most of the methods use planar meshes of tunable two-channel blocks; however, the schemes turn out to be sensitive to fabrication errors. We study a novel decomposition method based on multichannel blocks. We have shown that the scheme is universal even when the block's transfer matrices are chosen at random, making it virtually insensitive to errors. Moreover, the placement of the variable elements can be arbitrary, so that the scheme is not bound to specific topologies. Our method can be beneficial for large-scale implementations of unitary transformations by techniques, which are not of wide proliferation today or have yet to be developed.
将大型酉矩阵分解成较小的矩阵非常重要，因为它为实现经典和量子信息处理方案提供了途径。如今，大多数方法都使用可调谐双通道块的平面网格；然而，这些方案对制造误差非常敏感。我们研究了一种基于多通道块的新分解方法。我们已经表明，即使选择随机的块传递矩阵，该方案也是通用的，从而使其几乎对误差不敏感。此外，可变元件的放置可以是任意的，因此该方案不受特定拓扑的限制。我们的方法可以通过当今尚未广泛普及或尚未开发的技术，有利于大规模实现酉变换。
