Surface plasmon polaritons, in spite of being lossy, are known to preserve their coherence over long distances. In this paper, we investigate the coherence of surface plasmons propagating on a silver thin film surface using free-space optical Mach–Zehnder interferometry, where they are found to maintain their temporal coherence up to 80 µm, thus setting, for the first time to the best of our knowledge, a new limit. This can be important in applications integrating plasmonics with quantum information processing, where decoherence is a major challenge.

中文翻译：

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银波导中表面等离子体的时间相干性

尽管有损，表面等离子体激元仍然保持长距离的相干性。在本文中，我们使用自由空间光学Mach-Zehnder干涉技术研究了在银薄膜表面上传播的表面等离激元的相干性，发现它们在时间上的相干性保持在80 µm，因此首次将其设置据我们所知，这是一个新的极限。这在将等离子波与量子信息处理相集成的应用中非常重要，在这些应用中，相干性是一个主要挑战。