Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Phys Rev Lett. 2011 Oct 7;107(15):150401. doi: 10.1103/PhysRevLett.107.150401. Epub 2011 Oct 6.
A decoherence-free subspace (DFS) is an important class of quantum-error-correcting (QEC) codes that have been proposed for fault-tolerant quantum computation. The applications of QEC techniques, however, are not limited to quantum-information processing (QIP). Here we demonstrate how QEC codes may be used to improve experimental designs of quantum devices to achieve noise suppression. In particular, neutron interferometry is used as a test bed to show the potential for adding quantum error correction to quantum measurements. We built a five-blade neutron interferometer that incorporates both a standard Mach-Zender configuration and a configuration based on a DFS. Experiments verify that the DFS interferometer is protected against low-frequency mechanical vibrations. We anticipate these improvements will increase the range of applications for matter-wave interferometry.
无消相干子空间（DFS）是一类重要的量子纠错（QEC）码，它们被提议用于容错量子计算。然而，QEC 技术的应用并不仅限于量子信息处理（QIP）。在这里，我们展示了 QEC 码如何用于改进量子器件的实验设计以实现噪声抑制。具体来说，中子干涉仪被用作一个测试平台，以展示在量子测量中添加量子纠错的潜力。我们构建了一个五叶片中子干涉仪，它同时包含了标准的马赫-曾德尔配置和基于 DFS 的配置。实验验证了 DFS 干涉仪可以抵抗低频机械振动。我们预计这些改进将增加物质波干涉仪的应用范围。
