Classical wisdom of wave-particle duality says that it is impossible to observe simultaneously the wave and particle nature of microscopic object. Mathematically the principle requests that the interference visibility V and which-path distinguishability D satisfy an orthodox limit of square(V)+square(D)<=1. This work presents a new wave-particle duality test experiment with single photon in a modified Mach-Zehnder interferometer and convincingly show the possibility of breaking the limit. The key element of the interferometer is a weakly-scattering total-internal reflection prism surface, which exhibits pronounced single-photon interference with a visibility up to 0.97 and simultaneously provides path distinguishability of 0.83. Apparently square(V)+square(D)=1.63 far exceeds the orthodox limit set by the principle of wave-particle duality for single photon. It is expected that more delicate experiments in future should be able to demonstrate the ultimate regime of square(V)+square(D) approaching 2 and shed new light on the foundations of contemporary quantum mechanics.

中文翻译：

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在改进的 Mach-Zehnder 干涉仪中同时观测单光子的路径和干涉

波粒二象性的经典智慧说，不可能同时观察微观物体的波粒性质。从数学上讲，该原理要求干扰可见度 V 和哪条路径可区分性 D 满足 square(V)+square(D)<=1 的正统限制。这项工作在改进的 Mach-Zehnder 干涉仪中提出了一种新的单光子波粒二象性测试实验，并令人信服地展示了突破极限的可能性。干涉仪的关键元件是弱散射全内反射棱镜表面，它表现出明显的单光子干涉，可见度高达 0.97，同时提供 0.83 的路径可分辨性。显然square(V)+square(D)=1。63 远远超过了单光子波粒二象性原理设定的正统极限。预计未来更精细的实验应该能够证明平方（V）+平方（D）接近 2 的最终状态，并为当代量子力学的基础提供新的思路。